relax SVN archive

The optimisation of Monte Carlo simulations no longer changes the Q factors and back calculated data.

There was a bug in which the back calculated RDCs and PCSs, as well as the Q factors were being
calculated for each Monte Carlo simulation but stored in the non-MC sim data structures. Therefore
after MC sims, the Q factor and back calculated data would be that of the last simulation!!!

Added checks showing that Monte Carlo simulations in the N-state model modify the Q factors.

Fix for the calls to RelaxError in the N-state model return_error() method.

Fix for the N-state model error returning method for when errors are not present.

The spin_id variable was not defined.

Fix for the sample label matching - this is only performed if the sample label is given.

The sample conditions label is now being used to select the correct BMRB saveframes to read.

Removed the unused index.html.

Fix for the Rex scaling - the factor was incorrect!

Square brackets and commas are now also removed from the BMRB molecule name.

Fix for generic_fns.mol_res_spin.bmrb_read() for when no molecule name is present.