* Add a configurable hotkey to switch between window mode and fullscreen.

* Use !ConfiX for configuration.

* Make Ctrl-Alt-keys work.

* Optimization for the ViewFinder card with HexTile encoding: special
  update for 1-colour and 2-colour tiles. This requires a modification
  of the rectangle-aggregate generation. Suggestion: first be stricter
  on fusion, use several bounding boxes (instead of one), then apply
  the current method to the bounding boxes.

* ClientCutText and ServerCutText support on the RISC OS side.

* Implement XCursor.

* Add an option (and associated hotkey) to fix the mouse bounding box to
  the visible area of the window.
