Change the 'count' for COMPRESSED_TEXTURE_FORMATS from "?" to "-1". This

Change the 'count' for COMPRESSED_TEXTURE_FORMATS from "?" to "-1".  This
signals to the script (glX_proto_size.py) that generates the server-side
size functions that a handcoded query is needed to determine the data size.

Also do s/FOG_COORD_SOURCE/FOG_COORD_SRC/.

When initializing the count in glx_enum::__init__, cast the local property
to int.  Thanks to Python's dynamic typing, if this isn't done the type of
stored count will be a string instead of an int.