Resizable DynamicCamMaps

DynamicCamMaps will now be created and rendered to at your viewport size if your graphics card supports it (and has shader model 3--to ensure we don't try it on crappy cards). If we don't meet those conditions, then we fall back on the old artist supplied values.

This changeset also throws out a bit of cruft (but nowhere near enough). This means that we don't support really ancient cards from before 2005 any more. That's no loss.