package daemon: Rework error and issue propagation to client

* BDaemonClient: Move inner class BCommitTransactionResult to top level
and make it public.
* BCommitTransactionResult:
- Add a whole bunch of specific error code enum values. Such an error
code is now the primary error, as opposed to before where we would
mix status_t and enum value errors. There's a systemError property
of type status_t which may provide additional information, though
(depending on the primary error type).
- Remove the errorMessage property. Due to mapping all errors to the
specific error codes this is no longer necessary. Mixing such a
message with another error description is also not very helpful when
it comes to localization (still not supported, though).
- Add several properties (paths, strings, error codes) that serve as
arguments to the primary error and are used by FullErrorMessage().
- Add issues property, a list of instances of new class
BTransactionIssue. Those describe non-critical issues (e.g. failed
update of a settings file) that occurred in the process of
committing the transaction. Those issues should be presented to the
user by the package management program.
* Exception: Adjust to transport the BCommitTransactionResult
properties.
* CommitTransactionHandler, FsTransactions, Root, Volume: Adjust to
BCommitTransactionResult/Exception changes.
* CommitTransactionHandler: Now requires a BCommitTransactionResult to
which it adds the issues it encounters. The reply BMessage is no
longer needed, though.
* Volume: Refactor common code from the three methods that use
CommitTransactionHandler into new method _CommitTransaction.

BDaemonClient::CommitTransaction(): Align with documentation

The method is supposed to return B_OK as long as the _result object has
been initialized, even if committing the transaction failed. Fixes the
unhelpful error messages of pkgman when committing the transaction
failed for some reason.

BDaemonClient: add comment

BDaemonClient: Add support for creating activation transactions

* BActivationTransaction:
- Remove non-trivial constructor.
- Remove package list parameters from SetTo().
- Add AddPackageTo{Dea,A}ctivate().
* BDaemonClient:
- Add CreateTransaction(). It creates a transaction directory and
initializes a BActivationTransaction. Packages to de-/activate have
to be added afterwards.
- Add BCommitTransactionResult::FullErrorMessage().

package daemon: Add support for activation change request

* daemon: Handle new request B_MESSAGE_COMMIT_TRANSACTION. It activates
and deactivates given sets of packages. The new packages must be
placed in a directory in the administrative directory. The daemon
moves them to the packages directory and the deactivated packages to
a subdirectory it creates. It also save the old activation state
there.
* Add private BActivationTransaction, describing an activation change
transaction.
* BDaemonClient: Add CommitTransaction(), which sends a given
BActivationTransaction as a B_MESSAGE_COMMIT_TRANSACTION request to
the daemon.

Completely untested yet.

Implement getting a BInstallationLocationInfo

* Rename PackageDaemonDefs.h to DaemonDefs.h.
* Replace the MESSAGE_GET_PACKAGES by the new
B_MESSAGE_GET_INSTALLATION_LOCATION_INFO, which not only returns the
packages, but also other information about the installation location.
* daemon: Volume: Implement a change count which is bumped whenever
packages are activated/deactivated/added/removed. Cache the reply
for a location info request, using the change count to check whether
it is still up-to-date.
* Add private BDaemonClient for communication with the daemon.
* BRoster:
- Add GetInstallationLocationInfo() using BDaemonClient.
- Reimplement GetActivePackages(), using
GetInstallationLocationInfo().

package daemon: Rework error and issue propagation to client

* BDaemonClient: Move inner class BCommitTransactionResult to top level
and make it public.
* BCommitTransactionResult:
- Add a whole bunch of specific error code enum values. Such an error
code is now the primary error, as opposed to before where we would
mix status_t and enum value errors. There's a systemError property
of type status_t which may provide additional information, though
(depending on the primary error type).
- Remove the errorMessage property. Due to mapping all errors to the
specific error codes this is no longer necessary. Mixing such a
message with another error description is also not very helpful when
it comes to localization (still not supported, though).
- Add several properties (paths, strings, error codes) that serve as
arguments to the primary error and are used by FullErrorMessage().
- Add issues property, a list of instances of new class
BTransactionIssue. Those describe non-critical issues (e.g. failed
update of a settings file) that occurred in the process of
committing the transaction. Those issues should be presented to the
user by the package management program.
* Exception: Adjust to transport the BCommitTransactionResult
properties.
* CommitTransactionHandler, FsTransactions, Root, Volume: Adjust to
BCommitTransactionResult/Exception changes.
* CommitTransactionHandler: Now requires a BCommitTransactionResult to
which it adds the issues it encounters. The reply BMessage is no
longer needed, though.
* Volume: Refactor common code from the three methods that use
CommitTransactionHandler into new method _CommitTransaction.

BDaemonClient::CommitTransaction(): Align with documentation

The method is supposed to return B_OK as long as the _result object has
been initialized, even if committing the transaction failed. Fixes the
unhelpful error messages of pkgman when committing the transaction
failed for some reason.

BDaemonClient: add comment

BDaemonClient: Add support for creating activation transactions

* BActivationTransaction:
- Remove non-trivial constructor.
- Remove package list parameters from SetTo().
- Add AddPackageTo{Dea,A}ctivate().
* BDaemonClient:
- Add CreateTransaction(). It creates a transaction directory and
initializes a BActivationTransaction. Packages to de-/activate have
to be added afterwards.
- Add BCommitTransactionResult::FullErrorMessage().

package daemon: Add support for activation change request

* daemon: Handle new request B_MESSAGE_COMMIT_TRANSACTION. It activates
and deactivates given sets of packages. The new packages must be
placed in a directory in the administrative directory. The daemon
moves them to the packages directory and the deactivated packages to
a subdirectory it creates. It also save the old activation state
there.
* Add private BActivationTransaction, describing an activation change
transaction.
* BDaemonClient: Add CommitTransaction(), which sends a given
BActivationTransaction as a B_MESSAGE_COMMIT_TRANSACTION request to
the daemon.

Completely untested yet.

Implement getting a BInstallationLocationInfo

* Rename PackageDaemonDefs.h to DaemonDefs.h.
* Replace the MESSAGE_GET_PACKAGES by the new
B_MESSAGE_GET_INSTALLATION_LOCATION_INFO, which not only returns the
packages, but also other information about the installation location.
* daemon: Volume: Implement a change count which is bumped whenever
packages are activated/deactivated/added/removed. Cache the reply
for a location info request, using the change count to check whether
it is still up-to-date.
* Add private BDaemonClient for communication with the daemon.
* BRoster:
- Add GetInstallationLocationInfo() using BDaemonClient.
- Reimplement GetActivePackages(), using
GetInstallationLocationInfo().