* src/video_output/video_output.c: small change to allow the directx plugin to destroy/recreate picture buffers on the fly.

* Fixed the mute hotkey
* Fixed the positioning of some elements and removed the stupid black box
* Added speex and flac encoders to sout dialog

cddax and vcdx.

or absense of vcdx/cddax.

1. MRL's are of the form xxx://
2. Customize depending on vcdx/vcd or cddax/cdd
3. cdda doesn't have any such notion of a "Chapter", so remove
   the misleading :x.

For cddax/vcdx, I'm not sure though I think there is more to do.

  opened in blocking mode

* modules/stream_out/display.c: fixed segfault when switching audio/video track.

* modules/codec/libmpeg2.c: hack for demuxers which only have DTS timestamps.

* modules/mux/mpeg/pes.c: fixed to handle 0 pts/dts correctly.

* src/misc/mtime.c: fixed an overflow in mdate() on win32.
  This overflow was only affecting the hardware configurations where we can't use the performance counter and thus have to use GetTickCount().
  We now also check for the wrapping of the 32 bits value returned by GetTickCount() so mdate() doesn't wrap after 49.7 days.
* src/misc/win32_specific.c: call mdate() once in system_Init() so as to avoid thread safety issues while initialising the static variables used in mdate().

* added a lock when changing p_vout->p_last_osd_message

* added a the default CD Audio device in General Settings -> Input
* added OpenDialog::OnDiscPanelChange in wxwindows/open.cpp

* ALL: new main --video-on-top config option (in use by the x11/xvideo/osx/directx video outputs.)
* modules/video_output/x11/*: implemented support for "video on top". Will likely only work with KDE for now.

* modules/misc/dummy/*: new --dummy-save-es option to specify if we want the dummy
decoder to save the raw codec data to a file. This is disabled by default (while
it was always on before).
* src/input/es_out.c: bug fix for ES autoselection.

The last OSD message is now deleted before printing new one.

* modules/stream_out/transcode.c: added a floating point "scale" option for video transcoding. When specified, you don't need to specify the width and height of the output video.
 Also changed the width and height options so that if only one of them is specified, the other one is calculated automatically so as to keep the aspect ratio of the video.
* modules/mux/ogg.c: fixed crash when removing streams.
* modules/codec/theora.c: for now the theora encoder requires a width and height which are multiple of 16.