Fix DVD playback issues on some systems.

On some systems, DVD playback could stutter (fixes #5131) or fail completely due to an error related to copy protection (fixes #4969).

Both issues were caused by attempting to authenticate while fetching the DVD chapter information which is unneeded.
Capture bar: Fix a typo which resulted in a no-op.

Note that this is mostly a guess but getting the sign of the original biHeight seems to be what makes more sense. Some formats do use negative biHeight so it is sensible to keep the original sign.
(WIP/Broken) Disable the time tooltip shadow for incompatible video renderers.

Some video renderers cause the tooltip shadow to be replaced by an opaque black box.

Fixes #1415.
(WIP/Broken) Try to find out if VMR-7 uses overlays, without luck so far...
Don't force any background color for the Shockwave graph.

This commit fixes #1747.
WebUI: Inform the web interface that no audio stream is available.
WebUI: Make use of new [hasaudio] info.