relax SVN archive

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":

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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...

The PyMOL macro is registered as a pymol file in the results file structure rather than a Grace file.

The force flag now defaults to True for the molmol.write and pymol.write user function GUI pages.

Fixes for the pymol.write and molmol.write user function GUI pages.

The directory argument to the user function back end is now set to None as otherwise it defaults to
a directory such as 'pymol' which is then incompatible with the absolute file path from the file
dialog.

Added parsing of the "curve_type" argument.

Not clear if this is needed, but the code compiles.
This, however, does not solve the issue of relax thinking the C module is not compiled,
giving the following error message upon launching:

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ImportError: dlopen(/Users/semor/Documents/pse-4/collaborations/relax/relax-1.3_inversion-recovery/maths_fns/relax_fit.so, 2): Symbol not found: _curve_type
Referenced from: /Users/semor/Documents/pse-4/collaborations/relax/relax-1.3_inversion-recovery/maths_fns/relax_fit.so
Expected in: flat namespace
in /Users/semor/Documents/pse-4/collaborations/relax/relax-1.3_inversion-recovery/maths_fns/relax_fit.so
Relaxation curve fitting is unavailable, try compiling the C modules.
====

Created the model-free PyMOL macro functions by copying the Molmol ones.

This will need to be modified as Molmol commands are still being issued.

Fix for the results viewer window in testing mode - it is now not shown.