relax SVN archive

Fix for the structure.read_pdb and read_xyz user functions - set_mol_name should be strings!

Converted the sys_info user function to the auto-generation design.

Converted the structure user functions to the auto-generation design.

Fixes for allowing a default of 0 in a combo box.

Float and int numpy arrays and matrices are now supported for GUI user function args.

Fixes for most of the structure user functions - the pipe check is now performed at the start.

Converted the spin user functions to the auto-generation design.

The can_be_none value is now propagated into the Combo_list GUI element.

Fix for the Uf_container.add_keyarg() method for the wiz_combo_choices argument.

The argument defaulted to [] which is the problem! Then for every single user function argument
which does not provide a value for wiz_combo_choices will all be aliased to the same object! The
GUI code was then pre-pending the empty string to this list if can_be_none is set for the Value
object, modifying the list for all other user functions.

A number of fixes for the Combo_list GUI object.