[Shtoom] bug report: test_stunmapper et al. sporadic failure

[Zooko O'Whielacronx]

I thought that test_stunmapper et al. were failing due to their timeout 
being too short.  I thought this because they failed, I doubled the 
timeout, and then they passed.  However, right now I've set the timeout 
on test_stunmapper() up to 64 seconds, and it still fails about 1 out 
of 3 runs.

Regards,

Zooko