relax SVN archive

Updated the Wiz_window class docstring.

Redesigned the wizard page so that on_exit() replaces execute().

Spacing fix in the File_selector.__init__() docstring.

The new analysis wizard page now blocks and unblocks the next button.

This is done by using the wizard page on_display() method to block, and the button toggling
unblocks.

Created the wizard method block_next() to allow a page to prevent forwards progression.

All wizard buttons are now stored in self._buttons.

More of the wizard class variables have been made private.

The wizard list data structures are initialised now to 10 elements within the __init__() method.

This will allow for better tracking of all the data, without having to worry about appending to all
structures.

Converted many of the Wiz_window methods and variables to be private.

Removed the binding of wx.EVT_SHOW() for the wizard panels to the update() method.

This is now handled better by the on_display() method.