Merge branch 'master' of github.com:cooperative-computing-lab/cctools

Resolve difference between Dinesh's find_worker_by_random() and mine

Conflicts:
	sand/src/Makefile
	work_queue/src/work_queue.c
Merge branch 'master' of github.com:cooperative-computing-lab/cctools
Overwrite Ben's merge

Conflicts:
	work_queue/src/work_queue.c
Merge branch 'master' of github.com:cooperative-computing-lab/cctools
Change find_worker_by_random() from O(n^2) to O(n)
Check for successful task completion before putting output files into the cache.
Merge branch 'master' of github.com:cooperative-computing-lab/cctools