avmedia is a UNO component for audio/video media playing

Lives in avmedia/

Provides com.sun.star.comp.avmedia.* services/interfaces

  - Manager
  - Player
  - PlayerWindow
  - FrameGrabber

It is used in sd, slideshow modules

Impress uses it for sounds on slide transition and for embedded a/v objects

Porting to gstreamer:

 - added gstreamer backend to avmedia module
 - added it to scp2
 - modified sd to use gstreamer

TODO:

 - implement FrameGrabber (not sure if it is even used)

Notes:

 - Insert / Object / [ Sound, Video ] are disabled now (in
   sd/source/ui/view/drviews7.cxx). Comment says they are disabled
   because of a missing plugin. Looks like another redundancy. I guess
   I remove these as the Insert / Movie and Sound menuitem provides
   everything we need AFAIK. (when forced enabled, it adds a general
   object image - from kind of broken filechooser)
