Add a random chance to ignore a job to reduce contention
Add a random chance to ignore a job to reduce contention

This should probably be solved better (perhaps with a binary
exponential backoff).

Patch by: Sverre Rabbelier

--HG--
extra : convert_revision : svn%3A32761e7d-7263-4528-b7be-7235b26367ec/trunk%402994

rhyolight/nupic.son,rhyolight/nupic.son,rhyolight/nupic.son