relax SVN archive

The element name rather than atom name is being passed into the return_atomic_mass() function now.

Variable name fixes for the load_spins() function.

Fixed the atom_loop() call in centre_of_mass().

Fixed the atom_loop() call in load_spins().

Added the 'atom_id' arg to the structural API atom_loop() generator method stub.

The Scientific atom_loop() structural API method now properly returns the element name.

'_flag' has been added to all of the Scientific Python atom_loop() API method flags.

Added '_flag' to the end of all the flag args in the atom_loop() structural API method.

This will avoid many bugs with the flags being overwritten by other variables.

Updated the Scientific Python structural API atom_loop() method.

All the flags are now accepted, and the appropriate tuple is now built.

All the atom_loop() args in the API have been set to False.

This will make the method more robust as the caller will get exactly what it asks for, i.e. the
tuple will be of the right size.