* src/libvlc.h, modules/audio_output: added a global --spdif config option
   to allow using the spdif output by default if available.
* modules/misc/dummy/*: on win32 added a quiet mode that doesn't display
   a dos command box.
* modules/control/rc/rc.c: on win32 enabled the echo mode and the
   backspace key.
* modules/codec/mpeg_audio.c: fixed a sync bug.