relax SVN archive

Added all the icons sizes for the structure relax icon.

Added some initial graphics for the structure relax icon.

Fix for the structure.delete() GUI user function - the contents of nothing is now being added.

The wizard image now defaults to the relax icon.

Created the structure.delete() GUI user function and menu entry.

Fix for the default values of the NOE analysis page.

The base class method add_text_control() uses str_to_gui() to be sure that the initial value is a
GUI string.

Added the residue and spin menus to the spin tree window.

The menu binding only occurs if the parent object is supplied to build_menu_item().

Expanded the molecule menu entry in the spin tree window menu bar.

Fix for the menu build_menu_item() method - the function binding was not correct.