- be gentle to glenda, by allowing her to walk
   the shortest distance in a multi-step walk
   (found by using breadth-first search
    instead of depth-first search)
 - while walking with animation enabled,
   remain responsive, by splitting the
   animation of a walk in single-step
   moves that are 'scheduled' using etimer(2).
   This allows e.g. redirecting a walk during
   the animation, while glenda is still walking,
   or disabling animation during a walk.
 - reduce the amount of leaks reported by leak(1)
   by building the levels menu contents 'by hand'
   instead of relying on menuhit to call genlevel
   (would there be a way to avoid leaking while
    letting menuhit call genlevel?)
   Note: I still get some leaks, after popping
   up the B2 menu:
	    acid: src(0x00009627); // 4
	    /sys/src/libc/fmt/vsmprint.c:38
   I don't quite see where they come from.

Axel.