Merge pull request #3140 from dellis1972/develop

Updated Mac Content Pipeline to use FreeImageNET
Paths that don't start with a slash, shouldn't end up with one.
Merge pull request #3142 from danzel/fix-paths

ResolveRelativePath - Paths that don't start with a slash shouldn't end up with one
Fixed line spacing calculation in FontTextureProcessor
Merge pull request #3144 from SongArc/feature/spritefont_linespacing

Fixed line spacing calculation in FontTextureProcessor
Cleaned up some more things in FontTextureProcessor
Merge pull request #3145 from SongArc/feature/spritefont_cleanup

Cleaned up some more things in FontTextureProcessor
reverted previous change to FreeImageNET reference