GLMixer Code

Bug fix, cleanup and cosmetic improvements for management of queue when
changing marks at begin or end.

Avoid crash on error of sws_scale

new icons

Implementation of FAST FORWARD play on video file.
fix first picture fill up to eally match the mark in pts
changed icons of buttons

BUG fix access to picture queue in video refresh timer upate
well, was a bit optimistic thinking that no bugs were left..

Youhou! Got it all ok in VideoFile new implementation.

Working implementation of seeking behavior
- compatible with paused video
- two consecutive seek phases : in parsing thread (in packets) first and
in decoding thread (in frames) afterwards

Work in Progress: re-implementation of seeking and marking behavior to
match the new implementaiton of time and speed in video file

Bug fix : close VideoFile now ends all the libav threads (in codec
processor).

Implementation of varying size picture queue : the number of frames in
the buffer between decoding thread and display loop is based on the size
of the file (e.g. 10% num frames total) and is adjusted depending on the
play speed (larger if playing faster to allow decoder to read faster
forward when speed is higher).