strnlen: export its VLC pendant properly and check its existance in cc.c. Fixes the compilation onDarwin

Now vlc/vlc.h can be included out of the box.
However, I believe it will only work properly on little-endian 32-bits platforms.

This fixes the single largest source of problems when including vlc/*.h out of the box.

Standard MIDI File: don't abuse demux_vaControlHelper which is meant for sample-based audio files. This fixes the warping position and prevent uninplemented seeking.

Qt4- Playlist Model. Save the showColumn flags in the configuration ONLY during distruction and not while running.

Qt4 - Windows. Put the file extensions in a tree and in categories. Various checks on registry manipulation and on building of the dialog. Basically close #763

libass and asa as rendering backends. By equinox. Part of Google
Summer of Code

sponsored by Google Summer of Code

Summer of Code 2007

If the framebuffer hardware doesn't support double buffering in hardware, then do this in software. It will increase vout memory consumption by at least one output picture size, but will guarantee smooth subpictures in the video output.

- disable frame.pts only mp4v (seems to be bug concerning only that
  codec)
- initialize p_sys->i_hq to FF_MB_DECISION_RD if else ain't specified
  (seems like it's used uninitialised otherwise)
- set mb_lmin/mb_lmax and lmin/lmax also with qmin (ffmpeg documentation
  says lmax = qmax * FF_QP2LAMBDA) seems to help rate-control.