add frequently_accessed field to VdpBitmapSurfaceData (and store value)
+ softVdpBitmapSurfaceGetParameters
fix mistyping in error message
do query GL about softVdpBitmapSurfaceQueryCapabilities parameters
remove 4-byte crutch from test-005
change returned error in softVdpBitmapSurfaceCreate
tests: add test-007 (bitmap surface functions)