relax SVN archive

Removed the model-free and CSA info from the blacklisted spin variables.

This is to test the implementation of model-free and CSA BMRB saveframe reading.

Shifted the core of the model-free _select_model() method into _model_map().

This allows other parts of the code to translate model names to model-free equations and parameters.

Restored the reversal of the rotation matrix when determining Euler angles for a tensor in the PDB frame.

Fix for the test_read() unit test of generic_fns.relax_data.read().

The relaxation data structures are now handled differently in this branch and all data structures
have the same from for all spins, even if data is missing.

A few system and unit test fixes broken by recent rearrangements of the diffusion tensor code.

Caught when no diffusion tensor data is yielded by the bmrblib loop() method.

The restoration of the data from BMRB files into data pipes is now fully tested in the system tests.

The relaxation data reading is functional again, matching the new design of bmrblib.

The saveframe description for the relax scripts now says that they are relax scripts.

The spectrometer frequency is now converted to MHz before being sent to BMRBlib.