NetServices: include libnetservices2.a in the HaikuDevel package

Change-Id: I88e888df5ac7673ab343e25b7216546cb7ca6055
Reviewed-on: https://review.haiku-os.org/c/haiku/+/5799
Reviewed-by: waddlesplash <waddlesplash@gmail.com>
Tested-by: Commit checker robot <no-reply+buildbot@haiku-os.org>

haiku_devel: use relative symlinks to libraries in haiku package.

* This helps with creating a sysroot, otherwise extracted package
links refer to /system, which is outside of the sysroot.
* Should have no functional impact on Haiku, as these are already
symlinks

Change-Id: I29f719dc2c0839dd090e7f33eea0b8f98e0d6355
Reviewed-on: https://review.haiku-os.org/c/haiku/+/4218
Tested-by: Commit checker robot <no-reply+buildbot@haiku-os.org>
Reviewed-by: Adrien Destugues <pulkomandy@gmail.com>

libnetservices.a: create new static library for the network services

These will be added to the _devel packages so that other applications can link
to them.

Change-Id: If3fd231869823b42d6d896c6c9eb7a95c5fe715d
Reviewed-on: https://review.haiku-os.org/c/haiku/+/3666
Reviewed-by: Adrien Destugues <pulkomandy@gmail.com>

configure & build: Rework legacy GCC detection to parse versions outside of Jam.

Jam comparison logic is string-based, and so was detecting GCC >= 10
as being < 2. This rectifies that by removing the GCC version parsing
from Jam logic entirely, and setting various BuildConfig variables
instead.

Change-Id: I0c0ae3b9002fb5e77f9ca7a78600c91871657f03
Reviewed-on: https://review.haiku-os.org/c/haiku/+/3293
Reviewed-by: Adrien Destugues <pulkomandy@gmail.com>
Reviewed-by: Jérôme Duval <jerome.duval@gmail.com>
Reviewed-by: Alex von Gluck IV <kallisti5@unixzen.com>

libroot: Add fake libc static library

* It's specified in POSIX: https://pubs.opengroup.org/onlinepubs/9699919799/utilities/c99.html
* wine hardcodes a -lc in its winegcc compiler

Change-Id: I592b62085787d8f1a1ead2df32e978a91ab03ea9
Reviewed-on: https://review.haiku-os.org/c/haiku/+/3086
Reviewed-by: Adrien Destugues <pulkomandy@gmail.com>

libroot: Ship empty libpthread.a and libm.a for POSIX and general compatibility.

A few weeks back, I spotted in the Musl FAQ that they apparently ship
empty libm.a and libpthread.a files (https://www.musl-libc.org/faq.html),
which they said was for POSIX compatibility. A bit of digging got me to
http://pubs.opengroup.org/onlinepubs/9699919799/utilities/c99.html which
says:

> It is unspecified whether the libraries libc.a, libl.a, libm.a, libpthread.a,
> librt.a, [OB] [Option Start] libtrace.a, [Option End] libxnet.a, or liby.a
> exist as regular files. The implementation may accept as -l option-arguments
> names of objects that do not exist as regular files.

So to follow the letter of the law, we only need to have the "c99" command
accept these; however, it appears all Linux and BSD cstdlibs accept them
no matter what compliance mode is in effect.

Discussed with PulkoMandy. This will make HaikuPorts' job a lot easier...

libcolumnlistview: hybrid arch build, add to image

* This is a very useful control, and 3rd-party apps should be able to
use it.
* But, there are planned improvements (making a better model/view
interface) which prevents making it part of the stable API yet.

add libshared to the development packages.

* We install the headers for many things that are currently in libshared
(BColumnListView, BCalendarView, etc). So it makes sense to also provide
the lib in an "use at your own risk" way. Only the static library is
included, so apps linking against it should continue running on newer
Haiku versions even if the content of the lib changes.
* 3rd party application developers can now make use of those
experimental features without having to copypaste and fork the sources.

GL: Remove OpenGL kit, x86 Mesa

* Depend on Mesa packages to provide functionality

Add the secondary arch version of libroot_debug

Some gristing mixup caused the non-secondary version of the lib to be
added to the non-secondary directory, which is what the main
architecture HaikuDevel is already doing.

Add HaikuDevelSecondary package definition

It defines the haiku devel package for a secondary architecture
(haiku_<arch>_devel.hpkg).

libcolumnlistview: hybrid arch build, add to image

* This is a very useful control, and 3rd-party apps should be able to
use it.
* But, there are planned improvements (making a better model/view
interface) which prevents making it part of the stable API yet.

add libshared to the development packages.

* We install the headers for many things that are currently in libshared
(BColumnListView, BCalendarView, etc). So it makes sense to also provide
the lib in an "use at your own risk" way. Only the static library is
included, so apps linking against it should continue running on newer
Haiku versions even if the content of the lib changes.
* 3rd party application developers can now make use of those
experimental features without having to copypaste and fork the sources.

GL: Remove OpenGL kit, x86 Mesa

* Depend on Mesa packages to provide functionality

Add the secondary arch version of libroot_debug

Some gristing mixup caused the non-secondary version of the lib to be
added to the non-secondary directory, which is what the main
architecture HaikuDevel is already doing.

Add HaikuDevelSecondary package definition

It defines the haiku devel package for a secondary architecture
(haiku_<arch>_devel.hpkg).