relax SVN archive

Many fixes and much new code for the new structural container design.

Wrote the internal structural object __parse_structs() method.

This is used to loop over the structures within a model or the whole PDB if no models exist.

Started to redesign the internal structural object load_pdb() method.

Made the cpmg_frq() function accept only None for the reference spectrum and corrected a typo.

Corrected a few mistakes.

These were spot by Ed in a post at:
https://mail.gna.org/public/relax-devel/2009-01/msg00037.html
(Message-id: <7f080ed10901081128v5b8fe1edu7f654fb2e87d7bd1@...>)

Corrected remaining frq instances to cpmg_frq when appropriate to avoid confusion and corrected a
few related things in the system test script.

Added something in the user function cpmg_frq().

Yes, I had forgotten to put some code after the docstring..!

Added the user function cpmg_frq() and added examples to the user function cpmg_delayT().

Made a few changes so the cpmg_delayT() function now works.

Removal of the __init__() methods so that the model-structure data structure is not automatically created.