Fix most of the issues of the Equalizer.

(It begins to have a lots of "workarounds" :(

Qt4: add a file dialog needed by skins2 INTF_DIALOG_FILE_GENERIC, was available in wxWidgets, but it's not in Qt4
Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>

Close #1776

Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>

 - Fixes infinite loop when next_parse_offset = 0
 - Fixes memory access to invalid data with malformed ogg input.
Signed-off-by: David Flynn <davidf@woaf.net>
Signed-off-by: Derk-Jan Hartman <hartman@videolan.org>

Properly return pictures obtained from vout when they won't get
returned via the normal decodeBlock path.
 - Fixes lockup when seeking.
 - Maybe fixes win32 end of file fault.
Signed-off-by: David Flynn <davidf@woaf.net>
Signed-off-by: Derk-Jan Hartman <hartman@videolan.org>

YUVP is not activated because swscaler point resize is uglier than
scale.c

forced crop only for YUVP subpicture).
Separate scale module for YUVP and the others.
Fixed a segfault when no scale module is found.

If you think this commit is too much a feature than a bugfix, please revert.

Add Interfaces showed only 1 entry before.
Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>

Close #1757