relax SVN archive

Added a directory and a script for relaxation dispersion curve fitting system tests.

The next step will be to find published data to use in the tests. We will need data for the three
cases of slow-, intermediate-, and fast-exchange...

Started the implementation of the relaxation dispersion code.

The first step was to introduce the framework for system tests.

Removed an unused import.

Corrected a small typo in the development chapter of the manual.

Created a branch for the implementation of the relaxation dispersion code.

This follows a thread started by Seb at:
https://mail.gna.org/public/relax-devel/2008-12/msg00058.html
(Message-id: <4951148F.9050105@...>)

and continued by Ed at:
https://mail.gna.org/public/relax-devel/2009-01/msg00003.html
(Message-id: <7f080ed10901060854v3e0c1ac6idb8fad319e43c7de@...>)

Many corrections of formatting.

These were found using the relax 'code_validator' script (E. d'Auvergne) and mainly include trailing
whitespaces and missing empty lines before functions.

Add structural object load_pdb() methods now take the read_mol, set_mol_name, read_model, set_model_num args.

Fixes for 3 model-free unit tests using generic_fns.structure.main.read_pdb().

Passed the new args into generic_fns.structure.main.read_pdb().

Redesigned the structure.read_pdb() arguments and docstring.