depends: fix reace on native gettext installation
[osx] - adapt osx packaging - make it similar to what we do on ios and atv2 for consistency reasons
[osx/ios/atv2] - add XBMC_DEPENDS_ROOT and us it for constructing XBMC_DEPENDS - allows overwrite of XBMC_DEPENDS_ROOT when building with xcodebuild from commandline
[atv2/ios/osx] - add buildsteps for usage with jenkins