[osx/gtest] - fix linkage of xbmc-test binary (ffmpeg now needs expliciti linkage agaoinst framework VDA, and some new source files were missing in the makefiles)
[osx] - fix cmdline linkage of lixbmc.so and xbmc.bin - there is no circular dependency linker option on osx (e.x. -Wl,--start-group/--end-group) - so we still need to link in main.a for osx.
Merge pull request #3633 from Memphiz/cmdline

[osx] - fixed linkage of libxbmc.so, xbmc.bin and xbmc-test