relax SVN archive

The MoleculeContainer XML backwards compatibility hook now deletes the spin 'r_err' and 'r_sim' vars.

Fixes for the model-free system test check_read_results_1_3() method for the interatomic data design.

Modified the tylers_peptide.py model-free system test scripts for the unit vector calculation.

The structure.vectors user function has been replaced by dipole_pair.unit_vectors.

Fix for the XML file loading of the interatomic data container structures.

The backwards compatibility hook of the previous commit creates interatomic data structures,
hence they must be recreated from the XML first.

Added a backwards compatibility hook for converting old XML files to the interatomic data design.

This will convert the variable names, deleting the old, and create proton spins and interatomic data
containers populating them with the old spin parameters.

Fixes for the dipolar_pair.define user function backend.

The return_interatom() function now returns a list!

Updated the final_results_trunc_1.3_pre_py2.7.3_v2.bz2 results file for the interatomic data design.

The import of old relax 1.2 results files is now operational under the interatomic data design.

Basic docstring edit.

Bug fix for the printing out of interatomic data containers.

The __repr__() method wasn't skipping all methods.