relax SVN archive

Redesigned how the user function wizards are created.

The create_wizard() UF_base class method has been added to perform most of the work and to simplify
the specific user function code. The __init__() method has also been reintroduced, but this time it
takes the 'parent' arg, which is the parent wx.Window, via the User_functions package class.

Added the parent arg to the Wiz_window class.

This will allow the parent of the wizard to be specified, hopefully fixing the MS Windows window
ordering issues.

Removed the now useless UF_base.__init__() method.

The User_functions class no longer takes any arguments.

The interpreter singleton is now being used by the user function GUI pages.

Therefore all passing around of the self.gui class instance has been eliminated.

The relax GUI no longer starts maximised if debugging is on.

The script GUI user function is now operational again.

The interpreter object is now imported and the synchronous apply() rather asynchonous queue() method
is now used. This allows the execution lock to be released by the script at the end.

The script user function GUI element now uses wx.GetApp() to access to the relax controller window.

The GUI Main instance is now stored in the wx.App as self.gui.

This will allow access to the GUI class via wx.GetApp() calls, avoiding the need to pass the
instance around.

Fix for the script user function GUI element for opening the file dialog.