relax SVN archive

Created a new chapter for the relax user manual titled 'The relax data model'.

Fix for the pipe editor window screenshot width in the relax manual.

Converted some more wizard graphics to the EPS format for the user manual.

Updates and small expansion of the intro chapter of the relax user manual.

The user manual now specifies the repository revision if a non-tagged version is built.

This enables easier tracking and editing of the manual.

Updates to the generic_fns.mol_res_spin.id_string_doc documentation structure.

Updated the screenshot of the pipe editor window.

Created EPS versions of a number of wizard graphics for use in the user manual.

Removed some now useless whitespace from the top of each user function subsection of the manual.

Redesigned the formatting of the user function chapter of the relax manual.

The fetch_docstrings.py now forces each user function to start in a new column. This increases the
size of the manual, but makes the reading of the user function documentation much easier. The user
function class and function icons (128x128 format) are now placed between the top bar and the
subsection title and are left and right justified. This prettification simply allows the user
functions to be more quickly identified.