relax SVN archive

The ds.relax_gui data structure is initialised if absent when associating a pipe with a new tab.

The test_load_state_no_gui() GUI test is now more advanced, using the pipe editor to associate a tab.

The popup menu is not shown if the status.show_gui flag is not set.

The GUI test base class tearDown method now resets the observer objects.

This allows the GUI tests to function after the first.

Fixes for the analysis reset() method.

It has been renamed to post_reset() and now removes all the GUI elements itself. The call to
delete_all() is of no use because it calls delete_analysis() which removes data pipes and
ds.relax_gui data storage as well, and then notifies observers.

The auto-analysis initialisation can now associate with a pre-existing data pipe.

This is useful for bringing a data pipe into an analysis tab.

The data pipe editor now has a new 'Associate with a new auto-analysis' menu entry.

Added a hybridise button to the data pipe editor.

The pipe.hybridise user function window now uses the new Combo_list GUI element for pipe selection.

Created the Combo_list GUI element for presenting a dynamic list of combo boxes.

This is designed as a class rather than a wizard method to make it more extensible.