pkg_check_modules.cmake: On first run FindPkgConfig works properly but on second run it does not check if ${prefix}_FOUND is true, patch by Bjoern Ricks submitted by prahal.

pkg_check_modules.cmake: Update the version to work around http://www.cmake.org/Bug/view.php?id=6117 as spotted by prahal.

buildsystem/cmake: Add an embryonary CMake support. Files are constrained into the buildsystem directory so you need to populate them prior using it, using:
cd vlc && sh ./extras/buildsystem/cmake/scripts/convert_vlc_to_cmake.sh

Move the Mac OS X framework plus the yet to be finished VLC.app to projects/macosx/framework and projects/macosx/vlc_app.