Updated the author list for the submitted paper for the relaxation dispersion analysis.
Added the primary reference for relaxation dispersion in relax to the dispersion chapter of the manual.

This is the paper which is not published yet.
Removed the single quantum R1rho-type data reference in the introduction of the dispersion chapter of the manual.

This is redundant as R1rho data is always single quantum.
Backported the relax 3.1.3 CHANGES file addition to trunk.

The command used was:
svn merge -r22014:22015 svn+ssh://bugman@svn.gna.org/svn/relax/tags/3.1.3 .