#58 Add tracker for texture level information

[Bruce Merry]

ES doesn't have GetTexLevelParameter. Add a tracktexture filterset that will keep track of TexImage, CopyTexImage, CompressedTexImage, GenerateMipmaps, GENERATE_MIPMAPS and so on to keep track of the same information, and to provide functions to query this information.

Also rework the debug protocol so that debugger doesn't need to depend on extracting this information from the state dump, as a first step to having debug view of textures.