relax SVN archive

The spin loading wizard is now accessible from the tree's root menu in the spin viewer window.

Added a toolbar button to the spin viewer window to launch a wizard for loading spins.

A simple wizard has been created for the spin viewer window for loading spins which directs the user
to either the sequence.read user function or the structure.read_pdb and structure.load_spins user
functions. The wizard page Load_method_page has been added at the start to allow the user to choose
the method, and the last page Finish_page has been added so that the wizard can have a finish
button and terminal page.

Added a 32x32 sized relax icon for the spin.

Fix for the updating of the user function menu items in the main GUI window.

This was using the old self.entries_uf data structure.

The spin viewer window now uses the full user function menu of the Uf_menus class.

This should now remove the MS Windows bug whereby the spin viewer window would disappear to the back
after closing of the user function wizard dialogs.

Fixes for the auto-analysis wizards for the new user function GUI page design.

Fixes for the GUI tests for the new design of the user function GUI pages.

Converted all of the user function GUI pages to use the new create_wizard() base method.

This significantly simplifies the code. The functions also no longer expect a wx event.

The deselect user function GUI pages no longer expect the uf page to be returned.

Added the return_page arg to create_wizard() so that the user function page can be selectively returned.