relax SVN archive

Built the back end of the pymol.macro_run user function.

Renamed the PyMOL and Molmol macro user function back ends.

Modified the Molmol macro related user function front end to match those of PyMOL.

These are:
- molmol.macro_exec() is now molmol.macro_apply().
- molmol.write() is now molmol.macro_write().
- molmol.macro.run() has been added to execute macros from text files.

Some fixes and improvements to the PyMOL macro related user functions.

Created the front end for the pymol.macro_run user function.

This will be used to open and execute macros from text files.

Renamed the PyMOL macro related user functions in the prompt/script front end.

The pymol.macro_exec() function is now called pymol.macro_apply(), and pymol.write() is now called
pymol.macro_write() to make it clearer.

A first trial at passing the "curve_type" to the C code.

However, something is wrong, potentially in the C code (see
compilation warning below) as relax now complains that
"an integer is required" for assignment to "curve_type":

====
maths_fns/relax_fit.c: In function 'setup':
maths_fns/relax_fit.c:66: warning: assignment makes integer from pointer without a cast
====

Anybody, any idea ?

The PyMOL macro file extension is now correct in the pymol.write user function GUI page.

Replaced "PyString_AsChar" by "PyString_AsString" as the former does not exist...

Fixed the problem whereas the symbol "_curve_type" was missing...