Another update of the 'LM63 3-site' dispersion model test data.

This data now makes CPMGFit happy!
Added the CPMGFit results for the 'LM63 3-site' dispersion model test data.
Added the relax results for the 'LM63 3-site' dispersion model test data.
Added a warning not to use the 'LM63 3-site' model to the dispersion chapter of the user manual.
Added the 'LM63 3-site' dispersion model to the model list in the GUI.

It is not selected by default.