Fix after playback toggling in menu.

Also use check marks instead of bullet points.

Fixes #4799
Fix combobox width calculation on Vista Classic style.

Calculation is not 100% correct on every system, but it is better to have
more space instead of clipping.

Fixes #4758
Auto-fit cover-art image when loading audio file.

Add size limit (600px by default).

Ref: #4789
MainFrm: Be more clever when to repaint video frame.

- Fix OSD rapaint in paused state with vanilla EVR.
- Some minor fixes in after playback handling.

Fixes #4807
DVD: Allow jumping in paused state.
Add an option to enable/disable cover-art support.

Fixes #4789
MainFrm: Don't search for cover-art if both author and current directory
is the same.

Ref: #4789
PPagePlayer: Move icons higher.

Ref: #4758
Comment out some unused variable assignments.

Those can be useful if the functions are extended one day.
Don't force any background color for the Shockwave graph.

This commit fixes #1747.
Why "C:\tmp.srt"?
WebUI: Inform the web interface that no audio stream is available.
WebUI: Make use of new [hasaudio] info.
What the hell was intended here?!

Trying to make some sense of that code. Without much luck so far...