relax SVN archive

Fix for the test___residue_loop() unit test.

Simplification of the internal structural object atom_loop() method.

There is now only one block of code for the atom looping for the two options of the ave argument.

Deleted all unit tests for the ScientificPython structural object __molecule_loop() method.

This method no longer exists!

Fixes for the Scientific python structural object __residue_loop() unit tests.

Bug fix for the MolList.add_item() method.

The molecule name is now stored within the molecule containers.

Massive redesign of the Scientific Python structural object atom_loop() method.

The new structural data data structure is now handled, and a number of changes have occurred to the
class methods:

__molecule_loop() has been deleted.
__residue_loop() has been heavily modified.
The method __ave_atom_pos() has been added to allow the ave arg to atom_loop() to be handled.
The molecule type is stored in the molecule containers by load_pdb().

Added checks for the presence of the molecular data structures in the Scientific python structure.

The correct target molecule name structure is now passed into pack_structs() from load_pdb().

Compacted some comments.

Created the API base method target_mol_name() for generating the list of molecule names.