PPageFileMediaInfo: Various cosmetics.

Reduce the visibility of the member functions and variables and simplify the code.
PPageFileInfoRes: Various cosmetics.

Reduce the visibility of the member functions and variables and simplify the code.
Property dialog: Decide whether to show the "Resources" tab without checking the graph twice.
Property dialog: Ensure the focus stays consistent when switching to the "Resources" tab.

Previously the file name could get highlighted.
Property dialog: Make the UI more consistent between the tabs.

The header was slightly different on the "Resources" tab.
EVR-CP and Sync renderers: Remove useless use of interlocked functions.

The critical sections are lock protected so there is no need for interlocked functions which is a good thing being that those functions were badly used and did not protect anything anyway.

Fixes CID 1249711 and CID 1249712.
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...