relax SVN archive

Automatically converted the generic_fns.mol_res_spin module to support both Python 2 and 3.

The command used was:
2to3 -w generic_fns/mol_res_spin.py

For running relax with Python 2, the __builtin__.range() function has been replaced with xrange.

This causes large speed ups (speed that was lost with the earlier xrange() to range() conversions),
and memory decreases. For example on one system, the system test time decreased from 513.029s to
487.586s.

The compat module now has the py_version variable specifying if this is Python 2 or 3.

Import fix for the OpenDX mapping package, recently broken with the relative import for Python 3 change.

More usage of the is_unicode() function in the generic_fns.mol_res_spin module.

Created the check_types.is_unicode() function for Python 2+3 compatibility.

This is used in the generic_fns.mol_res_spin module.

Another raise() function call to statement change for 2to3 preparations.

Converted some raise() function calls to raise statements in preparation for the 2to3 conversion.

Converted the ScientificPython PDB reader to support both Python 2 and 3.

The command used was:
2to3 extern/scientific_python/IO/PDB.py -w

The __repr__() method was manually modified due to the 'list' variable clashing with the 'list'
type.

Created a new module for simultaneous Python 2 and 3 support in relax called 'compat'.