* Fix: remove executable argument in message from other instance
* Fix: pass through audio data when modification is not needed
remove non-resuable class
cosmetic change
* New: options for audio output driver, software volume, clipping method
add some convinience functions
* New: options for cache
* New: CMPLAYER_MPV_OPTIONS environment value for support mpv's options
* Mod: in 'modern' skin, change faster/slower to seek forward/backward
update build script
udpate mpv