relax SVN archive

Fix for the select.domain user function backend for the changes to the selection object.

Shifted the diffusion tensor structural object code to lib.structure.represent.diffusion_tensor.

The user function routes to pipe_control.structure.main.create_diff_tensor_pdb(), which pulls the
tensor info out of the data store, and then calls the diffusion_tensor() function of
lib.structure.represent.diffusion_tensor to create the representation, writes out a PDB file, and
finally adds the file to the data pipe's results file list.

Fixed some name classes in the namespace of pipe_control.structure.mass.

Shifted the cone geometric object representation functions to lib.structure.represent.cone.

The structure.create_cone_pdb user function first calls pipe_control.structure.main.create_cone_pdb()
which then calls lib.structure.represent.cone.cone(). This allows the pipe_control function to
write out the file and add it to the data pipe's results file list.

Removed the unit test of the parser argument of the structure.read_pdb user function.

The argument no longer exists.

Updated the lib package __all__ list.

Removed the no longer used parser argument for reading PDB files from some unit tests.

The lib.selection.parse_token() function is using the new Python way of splitting strings.

This is via the string's split() method.

Shifted parse_token() and tokenise() from pipe_control.mol_res_spin to lib.selection.

The pipe_control.mol_res_spin functions no longer use the selection object __contains__() method.

All functions now use the contains_*() methods of the lib.selection.Selection object.