relax SVN archive

Added the noe.spectrum_type user function page to the NOE peak intensity reading wizard.

Implemented the noe user function GUI pages and menu entries.

Improvements to the noe user function documentation.

Fix for the noe.read_restraints user function documentation.

Converted the noe user function docstrings to the new design.

The non-linear forking behaviour of the NOE peak intensity loading wizard is now implemented.

The wizard still needs the final noe.spectrum_type user function page, and only switching to
spectrum.integration_points if volume integration is specified.

Created the wizard set_seq_next_fn() method for supplying a function to determine which page comes next.

Created a page for setting the error type in the NOE peak intensity reading wizard.

Fix for the spectrum.error_analysis user function documentation.

A non-linear sequence of pages is now tracked for both correct 'next' and 'previous' behaviour.