tracediff: Don't highlight differences if the call nos are actually the same.
retrace: Allow multiple levels of debugging checks.
d3dretrace: Enable D3D9D when additional debug is requested.
d3dretrace: Terminate when CreateDevice fails.

Like we do for D3D10+.
d3dretrace: Force windowed mode on D3D9 traces.

Because there is no guarantee that the display mode is available.
gui: respect the alpha channel in surfaces

We weren't rendering any background which meant that surfaces
that were fully transparent would just show garbage that was
underneath. Lets make sure that the widget has a painted background
instead of garbage underneath.