relax SVN archive

Fix for bug #24723 (https://gna.org/bugs/?24723).

This is the bug that the mean RMSD from the structure.rmsd user function is incorrectly
calculated - it should be a quadratic mean.

The quadratic mean and quadratic standard deviation are now correctly calculated, and the
structure.test_rmsd, structure.test_rmsd_molecules, and structure.test_rmsd_ubi system tests have
been updated for the fix.

Implemented the per-atom RMSD calculation for the structure.rmsd user function.

Created the Structure.test_rmsd_spins system test for checking the per-atom RMSD calculation.

This is for the new option in the structure.rmsd user function.

Addition of the atomic boolean argument to the structure.rmsd user function front end.

This will be used to enable the calculation of per-atom RMSDs.

Small edits for the CHANGES file.

Updated the relax version number to 4.0.2 on the http://www.nmr-relax.com/api/index.html webpage.

Updated the relax API documentation at http://www.nmr-relax.com/api/4.0/ to version 4.0.2.

Added some more user function renaming redirects.

Updated the relax HTML manual at http://www.nmr-relax.com/manual/index.html to version 4.0.2.

Updated the http://www.nmr-relax.com/download.html webpage for the relax 4.0.2 release.