* Make the last tab on the top pane have the class of 'last'. Not used by the design now but might be by other designs later.
 * Don't return nothing when building a blocktype list and none can be found. This allows the template to output an informational message in this case instead.
 * Search $_POST only for the first action sent through (small optimisation rather than g&d work)
 * Because a lot of the buttons are now <input type="image">, the action is checked to see if it ends with _x or _y, and that part is stripped if it is found.