relax SVN archive

Created the to_5D() function for converting from matrix form to 5D vector form.

Some fixes for the to_tensor() function. The elements Ayx, Azx, and Azy were being referenced!

Created the to_tensor() function to convert from 5D vector to 3D matrix.

Docstring fix for average_rdc_5D(). The XH vectors must be unit vectors!

Created the average_rdc_tensor() function.

This is equivalent to the average_rdc_5D() function but takes the full tensor in numpy matrix form
rather than the elements of the 5D vector.

Created the average_rdc_5D() function.

This calculates the average RDC for an ensemble set of XH bond vectors, using the 5D alignment
tensor notation.

Created an empty module to dump RDC related computational functions into.

Fix for the N_state_opt class set up for the tensor optimisation.

Changed the N_state_opt functions to be model dependent.

The func_rdcs() method is now func_population(), and the func_tensors() method is now
func_2domain().

Modified the N_state_opt class to handle both alignment tensor and RDC optimisation.