Adapted paths for libraries within the dylibs.
Added header files for ogg, vorbis and libmpg123 to MacOSX build to avoid people having to get ahold of the music decorders when they want to build on OS X.
git-svn-id: http://svn.code.sf.net/p/quakespasm/code/trunk/quakespasm@435 af15c1b1-3010-417e-b628-4374ebc0bcbd
