relax SVN archive

Addition of a new test to the relax test suite.

The test creates three runs, two of which have S2 values set to 0.9 and 0.7. The difference is
calculated and assigned to the third run. If the S2 value of the third run is not ~0.2, then the
test fails.

Merged in revisions 2399 to 2437 of the main 1.2 line.

The command used was:
$ svn merge -r2399:2437 svn+ssh://bugman@.../svn/relax/1.2

Merged the change of revision 2397.

The command used was:
$ svn merge -r2395:2397 svn+ssh://bugman@.../svn/relax/1.2

Creation of a temporary branch to merge the changes from the 1.2 line into Chris MacRaild's branch.

Fix of bug #5670.

The bug report is located at https://gna.org/bugs/?func=detailitem&item_id=5670.

A single line in the self.set() function of the base class need changing by adding '* scaling'.

Bug fix #5659.

The link to the bug report is https://gna.org/bugs/index.php?func=detailitem&item_id=5659.

The problem was that the speicfic 'set()' functions were creating the objects called '*_error'
rather than '*_err'.

Completely reformatted the COMMITTERS file and added Andrew Perry to the list.

Removed the acknowledgment section of the manual.

Added the 'Discussing major changes' and 'Branches' subsections to the development chapter.

The 'user_name' tag has been replaced by 'xxxxx' in all examples of that chapter.

A few small edits to the development chapter of the manual.