relax SVN archive

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The 'user_name' tag has been replaced by 'xxxxx' in all examples of that chapter.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

Fixed the spacing after 'Gna!' in the manual.