[CLEANUP] Remove unused import statements (#264)

HaikuPorter: Remove old and obsolete maps from RecipeTypes.

arch: Add arm64 aka aarch64 since our toolchain now supports it

Fix copypaste error

Add sparc architecture.

architecture: Add riscv64 to fix bootstrap

RecipeTypes: Remove misleading self argument of YesNo.toBool().

Cleanup: Whitespace and line length cleanup.

Refactoring: fix indents by space (as we use tabs).

Refactoring: fix use of reserved keywords.

* Apparently, we were using reserved keywords as variable names, which
didn't seem to cause any problems, but could have done so in future
versions of Python.

Add some refactoring comments.

Revert to tab spacing for Pe's sake.

Try again with whitespace.

Second attempt to fix whitespace. Options are different on OS X.

Convert tabs to spaces.

Add ARM and M68K as valid platforms.

Add x86_64 as supported architecture.

Drop architectures inherited from MachineArchitecture.

Better protect against easy mistakes in recipes:

* explicitly check for dashes in names of provides and requires
declarations and complain if one is found

Change machine triple for x86_gcc2 to i586-pc-haiku

The old one was more correct in principle, but we'd have to apply that
change in the autotools as well and make sure that all build systems
using them still work. Too much work for little benefit.

Clean up trailing whitespace

MachineArchitecture: add findMatch()

Start with a build platform abstraction

* Add '--cross-devel-package' option to specify the path to the cross
development package. Can be used for cross-compiling.
* Add module BuildPlatform which exports a buildPlatform variable, which
is initialized to an instance of BuildPlatformHaiku or
BuildPlatformUnix as appropriate.
* Move findDirectory() to BuildPlatformHaiku. BuildPlatformUnix has a
version with some hard-coded mappings.
* Add PackageInfo class. Very simple ATM. It only extracts the version
and the architecture from a package file.
* Rework Main._initGlobalShellVariables() somewhat: Extracting the Haiku
version from the build platform's system haiku package is obviously
not correct when cross-building. Also add support for non-Haiku build
platforms.
* Remove no longer needed MachineArchitecture.getBuildTripleFor().

Add license header (MIT)

* additionally: uppercase copyright notices and separate them from the
top by a single line

RecipeAttributes: make 'extendable' tri-state

There are now two states for attributes that are extendable, which
specify what to do when the attribute has not been set for a package:
INHERITED to inherit the main package attribute's value and DEFAULT to
set the default value.

Remove unused MachineArchitecture.getForTargetTriple()

Drop TODO as it's not feasible.

Define explicit support for build, host and target architecture.

* added global configuration option HOST_ARCHITECTURE which defines the
architecture the resulting packages will be running on
* instead of TARGET_ARCHITECTURE, HOST_ARCHITECTURE has to be specified
for the cross-build repsository, TARGET_ARCHITECTURE needs only to be
set when it is different (e.g. when building gcc4 packages for a
x86_gcc2 Haiku)
* drop option '--target-arch', it doesn't make sense to switch the
target architecture on-the-fly, as the repository needs to be
repopulated after switching the architecture
* added boolean recipe type (YesNo)
* added global configuration option ALLOW_UNTESTED
* implement support for automatically accepting allowing untested ports
(via ALLOW_UNTESTED)

Rename i586-pc-haiku_legacy to i586-pc-haiku_gcc2

* makes it easier to grasp that this means gcc2

Automatically use 'source' architecture for source packages

* this brings the support for source packages to the point where
pkgman complains about not being able to install them

Introduce i586-pc-haiku_legacy

* use different gnu-triples for x86 and x86_gcc2 in order to be able
to keep them apart under all circumstances

Work on support for cross-building

* add detection of cross-build repository (via file .cross in root)
* add support for specifying target architecture via --target-arch
or via TARGET_ARCHITECTURE in haikuports.conf
* pull MachineArchitecture out of Architectures.

Add optional recipe phase PATCH

* ConfigParser does now determine which phases are defined in the
recipe.
* Port.patchSource():
- Call the recipe's PATCH(), if defined.
- If an error occurred applying a patch or calling PATCH() after at
least one patch has already been applied, clear the
checkout/unpack flags.

Drop executable flag from python modules

* pulled 'Package' out of 'Port' and adjusted everything to support creating multiple
packages from a single recipe file
Not many new features have been implemented yet, but building packages seems to work again.

Refactoring: rip haikuporter apart into separate modules

Refactoring: fix indents by space (as we use tabs).

Refactoring: fix use of reserved keywords.

* Apparently, we were using reserved keywords as variable names, which
didn't seem to cause any problems, but could have done so in future
versions of Python.

Add some refactoring comments.

Revert to tab spacing for Pe's sake.

Try again with whitespace.

Second attempt to fix whitespace. Options are different on OS X.

Convert tabs to spaces.

Add ARM and M68K as valid platforms.

Add x86_64 as supported architecture.

Drop architectures inherited from MachineArchitecture.

Better protect against easy mistakes in recipes:

* explicitly check for dashes in names of provides and requires
declarations and complain if one is found

Change machine triple for x86_gcc2 to i586-pc-haiku

The old one was more correct in principle, but we'd have to apply that
change in the autotools as well and make sure that all build systems
using them still work. Too much work for little benefit.

Clean up trailing whitespace

MachineArchitecture: add findMatch()

Start with a build platform abstraction

* Add '--cross-devel-package' option to specify the path to the cross
development package. Can be used for cross-compiling.
* Add module BuildPlatform which exports a buildPlatform variable, which
is initialized to an instance of BuildPlatformHaiku or
BuildPlatformUnix as appropriate.
* Move findDirectory() to BuildPlatformHaiku. BuildPlatformUnix has a
version with some hard-coded mappings.
* Add PackageInfo class. Very simple ATM. It only extracts the version
and the architecture from a package file.
* Rework Main._initGlobalShellVariables() somewhat: Extracting the Haiku
version from the build platform's system haiku package is obviously
not correct when cross-building. Also add support for non-Haiku build
platforms.
* Remove no longer needed MachineArchitecture.getBuildTripleFor().

Add license header (MIT)

* additionally: uppercase copyright notices and separate them from the
top by a single line

RecipeAttributes: make 'extendable' tri-state

There are now two states for attributes that are extendable, which
specify what to do when the attribute has not been set for a package:
INHERITED to inherit the main package attribute's value and DEFAULT to
set the default value.

Remove unused MachineArchitecture.getForTargetTriple()

Drop TODO as it's not feasible.

Define explicit support for build, host and target architecture.

* added global configuration option HOST_ARCHITECTURE which defines the
architecture the resulting packages will be running on
* instead of TARGET_ARCHITECTURE, HOST_ARCHITECTURE has to be specified
for the cross-build repsository, TARGET_ARCHITECTURE needs only to be
set when it is different (e.g. when building gcc4 packages for a
x86_gcc2 Haiku)
* drop option '--target-arch', it doesn't make sense to switch the
target architecture on-the-fly, as the repository needs to be
repopulated after switching the architecture
* added boolean recipe type (YesNo)
* added global configuration option ALLOW_UNTESTED
* implement support for automatically accepting allowing untested ports
(via ALLOW_UNTESTED)

Rename i586-pc-haiku_legacy to i586-pc-haiku_gcc2

* makes it easier to grasp that this means gcc2

Automatically use 'source' architecture for source packages

* this brings the support for source packages to the point where
pkgman complains about not being able to install them

Introduce i586-pc-haiku_legacy

* use different gnu-triples for x86 and x86_gcc2 in order to be able
to keep them apart under all circumstances

Work on support for cross-building

* add detection of cross-build repository (via file .cross in root)
* add support for specifying target architecture via --target-arch
or via TARGET_ARCHITECTURE in haikuports.conf
* pull MachineArchitecture out of Architectures.

Add optional recipe phase PATCH

* ConfigParser does now determine which phases are defined in the
recipe.
* Port.patchSource():
- Call the recipe's PATCH(), if defined.
- If an error occurred applying a patch or calling PATCH() after at
least one patch has already been applied, clear the
checkout/unpack flags.

Drop executable flag from python modules

* pulled 'Package' out of 'Port' and adjusted everything to support creating multiple
packages from a single recipe file
Not many new features have been implemented yet, but building packages seems to work again.

Refactoring: rip haikuporter apart into separate modules