relax SVN archive

Bug fix for the generic_fns.sequence.load_PDB_sequence() function.

The function no longer fails if a chain or segment id is present in the PDB file.

Modified the cone_edge() function to accept the residue name as an argument.

Modified the cone_pdb() function so that the cone edge and cap are now the same residue.

Removed some debugging code.

Wrote the stitch_cap_to_cone() to join the cap of a cone to the cone edge.

This is being called from the specific_fns.n_state_model.cone_pdb() function.

The max_angle arg is now being respected. The generate_vector_dist() is complete.

Docstring fix for the generate_vector_dist() function.

Bug fix in the generate_vector_dist() function.

The centre of the distribution is called 'centre' and not 'R', as it used to be for the diffusion
tensor.

The call to generate_vector_dist() from cone_pdb() now passes in the 'CON' residue name.

A number of fixes for the new generate_vector_dist() function.