#14 everything should be AJAX

[Scimonster]

The page should never visibly refresh, never change the base URL. It should always stay on index.php. All updates should be done via AJAX.

[Scimonster]

This has started as of [r13]. It will take a little while to get back to where we had been, but it's OK.
This also allows for a browsing history, and real undo/redo while editing, because save doesn't have to refresh the page, clearing the browsers' form change history.