Cleaning up old C header code from convert, we'll just deal with Khronos
XML files now. If there's a need for parsing C headers we should do that
as a separate tool that either parses and generates the OpenTK XML specs
directly generates Khronos XML specs that can then be parsed by Convert.
Signatures were split into 4 APIs before (gl, glcore, gles1, gles2).
However, gles2 contains bindings for both version 2.0 and 3.0. The
version information is now maintained, which allows us to cut down on
the number of generated enumerations.
As a sideeffect of the group element definition, the parser will
convert a ptype of "const GLubyte *" with a group of "String" to
"String *", which is not the correct result. GLXmlParser will now
detect and fix this condition that affects the GetString function of
families.
Deprecated elements are marked as such in the compatibility profile and
are completely absent from the core profile. This is in-line with the
new glcore headers from Khronos.
Use a stable sort for generated elements, in order to make the generated
file work better with version control. Extension names are now extracted
directly from function names - solves issues with functions that are
defined in multiple extensions.
