Update MultiMon link.
Updated LAV Filters to 0.63-5-7ffa765 (custom build based on stable version 0.63.0).
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.
What the hell was intended here?!

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