Add script to download the right Linaro toolchain and use it for compilation
Build all packages in out/build

This makes it easier to remove all builds by removing a single directory
(without removing the sysroot)
Fix environment for compiling user-space programs

Fix the environment such as the compilation of user-space programs
finally succeeds. This includes:

- Set various PKG_CONFIG_* variables to that pkg-config knows where to
  look (and *not* to look) for its library configuration files
- Use the system pkg-config instead of the Linaro toolchain's, which is
  old and does not handle PKG_CONFIG_SYSROOT_DIR correctly. We hope that
  the local pkg-config is new enough.
- Fix CCFLAGS and CXXFLAGS so the compiler uses the rootfs as its
  sysroot and knows where to look at
- Add a --with-sysroot option to the call to autogen.sh so that
  libtool knows it needs to prefix library paths in .la files with it

While we are at it, we also get the right number of processors to pass
to make -j.
mesa: tune configuration options

GLX can be enabled for the case we support X some day.
Use highlighted status macro to report status in scripts

This is more visible than a simple echo. Also only download the L4T root
FS and drivers pack if needed.
Add script to prepare L4T image for OSS graphics stack compilation

prepare-rootfs will perform the following:

- Download and install qemu-static-arm into the target FS to allow to
  run ARM binaries from chroot on an x86 host
- Temporarily replace the target FS's resolv.conf to enable network
  access
- Chroot into the target FS and run apt-get to download the dependencies
  required for the OSS graphics stack compilation
- Fix the absolute libraries symlinks so they can be resolved during
  cross-compilation.
weston: set permissions of weston-launch after install
Make script execution stop in case of error
Indicate success at the end of each compilation script
Cleanup build scripts and add success message

Make the configuration options more readable, factorize some code, and
indicate successful installation of packages.
Use same compilation scheme for Linux and Nouveau

Use the same compilation scheme as other packages for Linux and Nouveau,
namely:

- build into out/build/
- perform installation within build script
- install into $SYSROOT
- use the downloaded cross-compilation toolchain

Result boots and is usable, yay!
linux: preserve L4T kernel and DTBs, generate u-boot script
Only set CROSS_COMPILE environment variable if not present
Add script to build kmscube
Only run autogen.sh when needed

If we re-run a build script that has already been configured, skip the
call to autogen.sh and invoke make directly. Make will automatically
invoke configure again if needed.
Update pthread-stubs script

This is not needed for L4T but will be if we support Arch Linux images
in the future, so keep it around for now.
Merge pull request #2 from Gnurou/master

Make user-space libraries and programs