rebased on upstream

ffmpeg is now removed from tree. now pulled in
through bootstrap library support
added: (skeleton) ffmpeg based image loader
changed: enable tests by default, but don't build them

add a 'make check' target which builds tests and executes
rebased on upstream

- make MAD codec optional and remove support in dvdplayer
- generate json header
- X11 windowing events
rebased on upstream

- install new icons
rebased on upstream

- add new subdirectory media
added: basic ffmpeg based tag loader

use this for .mka
added: chapter support for .mka files
changed: GnuTLS is only required by FFMPEG

don't probe in main buildsystem
remove invalid brace