relax SVN archive

Changed the struct_index arg of the structure.write_pdb() user function to model_num.

Renamed the struct_index arg to model_num in write_pdb().

Fixes for the cone_pdb() method for the new structural data design.

Fixes for generate_vector_dist(), generate_vector_residues(), and stitch_cap_to_cone().

These now handle the MolContainer instance.

Modified create_diff_tensor_pdb() for the new structural data design.

A large number of fixes for the write_pdb() method.

It can now handle the new structural data design.

Updated mf_csa.py to the 1.2.10 branched ellipsoidal CS tensor code.

This code comes from Pavel Kaderavek <kada att chemi dot muni dot cz> and is located at
https://www.ncbr.chemi.muni.cz/~kada/relax-1.2.10_cst.tar.

Created, by 'svn cp', the mf_csa module.

Copyright updates.

Fixes for create_vector_dist() for the new structural data design.

The atoms are added to the single molecule, and the struct_index has been eliminated.