Known bugs:

- Enlargements seem to need silly amount of memory.  Where's it all going ?

- Middle mouse drags sometimes don't seem to have any effect other than
  triggering redisplay.  Thought to be fixed by MutatableImage serial numbers
  (was using pointer value as substitute for object identity before).

- Build dependencies don't seem to be very good; crashes and bad linkage
  can sometimes be cleared by touching files or rebuild from clean.
  (precompiled headers something to do with this?)
  We're at the mercy of qmake here really.

- Simplifying functions sometimes changes their appearance
  (implies "is_constant" probably buggy for some functions).
  Some random testing of functions before and after simplify would help.

- When using -spheremap mode, middle mouse-button adjustments don't work
  as expected (this is because they're not compensated for the projection).
  Live with it.

- Gradient type operators produce a real mess when applied to
  noise functions.  High frequencies in the noise produce big derivatives.
  Enlarging up to 4096x4096 sometimes looks a bit more sensible.

- Have yet to find a tool which can display anything other than the
  first frame of a Qt-generated MNG format.  (Apparently Qt's MNG
  actually has nothing to do with the multi-frame PNG format).

- Very rarely image calculations appear to arrive seriously out-of-order.
  May be a more of a problem on slower hardware ? 
  If this is causing trouble, try using "-t 1" command-line option to fix it.

- Example of "interesting" fullscreen bahaviour (Metacity on RedHat9):
    Run app fullscreen.
    Fire off a fullscreen "Big" display.
    Open the properties dialog for the "big" window.
    This results in metacity showing the task bar.
    Use the task bar to select the main app window into the foreground.
    Watch both fullscreen windows battle for supremacy!
  This sort of thing is unlikely to be fixed.

- Resizing the evolvotron window queues up crazy numbers of tasks.
  This didn't matter too much in 2D mode, but with animations the
  memory reserved for each task's render target is considerably larger. 

- Undo doesn't always work how you'd expect.
  e.g respawn after undo doesn't respawn from what you'd expect.
  Undo of a reset or restart doesn't put the mutation parameters & function weightings back how they were.

- Moire patterns & undersampling mean small images can show structures
  not actually present in larger resolution versions.

- Once image colours become saturated there's not much which will cause
  them to scale back down to sensible ranges, unless you're lucky.

- Recolour behaves strangely sometimes (?)
  (e.g spawns all-black images or subtly warped images)
  Not seen recently; may be fixed.

