correct mod division bug for rank sending token to rank 0
drop extra send from token termination
ensure that source rank keeps an item when sending work
return terminate/msg flags in wait_on_probe, remove unnecessary call
randomize first task to request work from
use rand_r instead of srand
Merge pull request #10 from adammoody/master

rank=-1 bug on rank 0, return terminate/msg flags in wait_on_probe