relax SVN archive

Updated the news announcement link for relax version 3.1.1 at http://www.nmr-relax.com/download.html.

The correct link is https://gna.org/forum/forum.php?forum_id=2423.

Updated the relax API documentation at http://www.nmr-relax.com/api/3.1/ to version 3.1.1.

Updated the version number to 3.1.1 on the webpage http://www.nmr-relax.com/api/.

Updated the HTML version of the relax manual to version 3.1.1.

This is for http://www.nmr-relax.com/manual/index.html.

Updated the http://www.nmr-relax.com/download.html webpage for relax version 3.1.1.

Added the relax 3.1.1 manual to the repository.

Updated the version number to relax 3.1.1.

Backported the relax 3.1.1 CHANGES file addition to trunk.

The command used was:
svn merge -r21934:21935 svn+ssh://bugman@.../svn/relax/tags/3.1.1 .

Updated the CHANGES file for relax version 3.1.1.

relax version 3.1.1.

This is a minor feature release which adds support the 'NS MMQ 3-site linear', 'NS MMQ 3-site',
'NS R1rho 3-site linear', and 'NS R1rho 3-site' relaxation dispersion models. There is also
improved support for R1rho data sets where multiple offsets and multiple spin-lock fields have been
collected for each spin.