[build] build gtk-sharp from svn, fix up .configs
[build] build gtk-sharp from svn, fix up .configs

The gtk/gdk-sharp-2.0 assembly config files map to the x11 variant
of the GDK/GTK native libraries, so after make install we change
them to map to quartz.

bl8/bockbuild,BansheeMediaPlayer/bockbuild,BansheeMediaPlayer/bockbuild,bl8/bockbuild,bl8/bockbuild,mono/bockbuild,BansheeMediaPlayer/bockbuild,mono/bockbuild