relax SVN archive

Removed the Page_storage singleton object as the idea does not work.

While the pages cannot be recycled, a fundamental problem is if a wizard with the page is run at
the same time as the user function page. More than one copy of the page must exist at the same
time!

Advancements for the auto-generated GUI user functions.

String list GUI elements are now supported. The wizard element are now updated on display, allowing
for example the current set of data pipes to be displayed in the ComboBoxes of the pipe user
functions.

The List and Combo_list class now have ResetChoices() methods.

This allows these elements to fit with the auto-generated GUI user functions.

Big set of changes enabling the auto-generation of the GUI user function front ends.

This will create user function objects which are bound to the menu items, and the user function page
objects automatically from the user_function data object. The pipe user functions have been updated
to supply the needed data, and additional arguments have been added to the Uf_container.add_keyarg()
method. The Uf_container object can now accept additional wizard related variables.

The graphics package image variables are now imported into the paths module.

This is for backwards compatibility with the old user function pages.

Shifted a number of the image path variables from the gui.paths module to the graphics package.

Whitespace fix.

The user function GUI menu item is now being auto-generated.

This will require future work to support user functions not within a user function class.

The graphics.fetch_icon() function now returns None if no icon is specified.

Created the graphics.fetch_icon() function for a better API for the icon paths.

This will eventually replace the gui.paths module.