This also allows hiding static songs; I added that since it took about four
lines extra code.
Note that I've updated the Save() function a bit, and fixed some bugs
I saw, but it's not used yet and it's no more tested than it was before.
Finding out which songs were random was broken: if a non-static
song (eg. player's best) was missing ("BEST99999"), m_entries
doesn't necessarily match one-to-one with the results of GetStageInfo.
The masking uses the Z-buffer under the assumption that some cards don't have a stencil. Should we be using the stencil instead? It doesn't really matter because we never need both the Z buffer and stencil buffer simultaneously.
Glenn Maynard