Adding a test to verify a bucket type is visible from a number of nodes
since the active status is given as long as the claimant sees it. But
requests to other nodes can end up hitting the dreaded {error, no_type}.
Also added a general utility that can be used for bucket type checks and
for general verification of bucket properties across nodes.
The mapred_test eunit suite had a fragile setup stage that frequently
caused the automated builders to fail. It should be more stable here.
The suite has also been broken into several independent tests, to make
it possible to run each major piece individually.
