relax SVN archive

Added colons to all entries of the abbreviation chapter in the relax user manual.

Updated and completed the installation chapter of the relax user manual.

A lot of the text was 4-6 years out of date.

Fix for the scons 'install' target for the byte-compilation of the *.pyc files.

Running 'relax --test' no longer byte-compiles the files, so instead 'python -m compileall .' is
being used instead.

Fix for the chi2 references in the maths chapter of the relax user manual.

Expansion and completion of the model-free chapter of the relax user manual.

A large number of changes have been made to complete the chapter and description of all model-free
sample scripts. The dauvernge_protocol.py script is now fully described.

Updated the http://www.nmr-relax.com/download.html webpage for the relax 1.3.15 news item.

This news item is located at https://gna.org/forum/forum.php?forum_id=2343.

Updated the http://www.nmr-relax.com/download.html webpage for relax 1.3.15.

Some small edits to the release checklist document.

Removed more maths from the HTML user manual section titles.

This is using the \latexonly and \htmlonly constructs to toggle titles.

Updated the API documentation to relax version 1.3.15.