relax SVN archive

Fixes for the grid GUI elements - the first row which is not deleted is now being cleared of all text.

The data pipe editor can now be opened with Ctrl+D.

Fix for the popup menu in the data pipe editor - the row and column were swapped.

Fixed an accidentally deleted import of the status object.

Changed the pipe_switch observer object to pipe_alteration and all pipe changes are now signalled.

Implemented the data pipe editor window.

This will be used to manipulate data pipes including how they interact with the GUI.

Converted the menu build_menu_item() method into a function of gui.components.menu.

This allows it to be used more easily by other parts of the GUI.

Comment fix.

Created page_index_from_pipe() and page_name_from_pipe() to obtain page info for a given data pipe.

Created a cropped version of the data pipe graphic.