relax SVN archive

Added a few new argument checks for arrays and matrices of floats.

These are:
is_float_array()
is_float_matrix()

Added a few new RelaxError classes.

These include:
RelaxNoneListFloatError
RelaxMatrixFloatError
RelaxNoneMatrixFloatError

The BaseArgError class was also modified to handle the length arg (now the size arg) being a tuple
for matrix sizes.

Fix for the frame_order.cone_pdb user function.

The create_cone_pdb was referencing a non-existent variable!

Fix for the set up of Monte Carlo data for fixed alignment tensors in the N-state model.

The _minimise_setup_fixed_tensors() method has been fixed to return the actual tensor rather than
simulation for the fixed tensors, as there is no simulation tensor in that case.

The N-state model Monte Carlo simulations can now handle fixed alignment tensors.

Created the alignment tensor module return_tensor() function for returning tensors.

This takes fixed tensors into account, skipping them if the skip_fixed flag is set.

Created the alignment tensor module num_tensors() method for counting tensors.

This excludes fixed tensors by default.

The rdc and pcs display and write user functions now output mol, res, and spin name and num cols.

Instead of the spin ID column, these user functions now output the molecule name, residue name,
residue number, spin name and spin number columns. This is better to read back into relax as info
such as the spin number can be ignored to allow different PDB files to be used.

Bug fix for the relax_io.read_spin_data() function for spin IDs.

Spin IDs can now be handled if they are the first column in the data file!

Created a system test with RDC data for loading RDCs from a file with spin ID strings at the start.