relax SVN archive

A few modules which should have been committed at r16589!

Converted all of the user functions to use the Desc_container class design.

All of the user function descriptions, prompt examples, and additional documentation scattered
around the relax sources have been merged into the Uf_info.desc list of Desc_container objects.

This large set of changes currently breaks the GUI and is not compatible with the user manual
compilation, but should simplify and speed up both of these once converted.

Fix for the Test_uf_objects.test_uf_object_build_doc() unit test.

The deleted 'prompt_examples' and 'description' variables are not passed into the prompt user
function objects.

The 'prompt_examples' and 'additional' uf structures are no longer passed into the prompt objects.

Removed the 'prompt_examples' and 'additional' variables from the Uf_info containers.

These have been superseded by the Desc_container objects.

Prompt examples are now followed by 2 newlines in the prompt help strings.

This restores much of the original formatting for these examples.

Added support for no spacing in tables for the prompt help strings.

The Desc_container.add_table_titles() method now accepts and stores the 'spacing' arg. This is
passed all the way into the prompt help system to format the tables with.

Fix for the wrapping of tables for the prompt help strings.

Sometimes the total_width was not being reset to the maximum allowed width of status.text_width.

Added a check in the prompt help _build_doc() method for the uf description.

This should, together with the _build_doc() unit tests, help to uncover all unconverted user function
'desc' variables.

Created an algorithm for wrapping table columns to fit within status.text_width.

This if for the prompt user function docstring tables. The columns are now dynamically wrapped so
that the table will not be wider than the given width. For example the value.set user function
description table would normally have a total width of 238 characters, but this now fits within one
screen of text under all operating systems.