Known bugs:

- Patterns pop-up sometimes comes up with 0 size
- Strange line clipping bug, seen when grid display is on.
- Strange stretching effects when arms cannot reach specified point
- When 'steering' the centre of interest or hand positions I should use
transform the direction by the inverse of the viewing transform, so
things move in a sensible way.
- The 'reset position' button on the hand editor menu unposts the pop-up.
- Hands do a funny jive when doing 2's 
- It's even funnier with dwell set to 0!
- Occaisional lock-ups (related to signal handling ?)
- Is the real-time behaviour really correct? 
- The arm positions sometimes end up in very funny places.


Desirable features:

- Add options to load and save patterns and settings to file.
- Add 'hands' to the arms
- Use a finer resolution for the dwell control. (This is tricky to implement)
- Build a nicer polygon mesh for the robot!
- Give robot a face. Animate it.
- Improve the props (especially knife!) and add more
- Do hidden object removal - clubs behind clubs, etc.
- Model 'scooping' more accurately - accelerate and decelerate objects correctly
- Keyboard accelerators for common button presses

- Ability to specify passing patterns? Multiple jugglers?
- Dynamic hand motions (Mills Mess etc.)


