Changed all references from Molmol to PyMOL in the PyMOL code. The macro fns raise RelaxErrors.
The 'self.macro_exec()' and 'self.write()' functions raise RelaxErrors saying that the functions
have not been implemented yet. The 'pymol.cartoon()' user function has been shifted to the top of
the function list in the 'prompt/pymol.py' file.
