* added matroska, dvb and pvr USE vars.
* enabled support for flac.
* removed libdv support since it's deprecated
* enabled freetype support if USE=truetype
* enabled satellite support if USE=dvb
* added local USE variable pvr to compile with pvr support
* added local USE variable matroska to compile with experimental matroska
  support/ebuilds. See also http://forums.gentoo.org/viewtopic.php?t=63722&highlight=matroska.