relax SVN archive

Creation of a branch for fixing bug number 5559.

The bug report is located at https://gna.org/bugs/index.php?func=detailitem&item_id=5559

Editing of the entire development chapter of the manual.

A few changes to the open source infrastructure chapter.

Spell check of the two manual chapters.

Renamed the file of the open source infrastructure chapter.

Wrote the 'Variable, function, and class names' subsection of the development chapter of the manual.

All the new lines from the end of the 'exampleenv' environments in the manual have been removed.

Major changes to the development chapter of the manual.

The relax-announce mailing list is now included in the intro.

All sections have been significantly edited.

An empty subsection called 'Variable, function, and class names' has been added.

The section 'Committing conventions' has been added and the subsection 'Format of the commit logs'
has been written.

The 'Making changes' section has been added and consists of two subsections, 'Patching' which came
from the start of the chapter and 'Becoming a committer' which describes what is needed to become a
committer.

Major changes to the 'web' manual chapter including a name change to 'Open source infrastructure'.

All sections have been heavily edited.

The 'Downloads' section has been renamed to 'The relax distribution archives' and has been
significantly extended.

Modified the behaviour of the Sconstruct clean target to remove 'relax.out' from the LaTeX dir.