Initial work at better task allocation
Use meanActiveTasks as a tiebreak when availSlots are equal. Add tests for this behavior.
Revise method signatures.
Minions report meanActiveTasks as a percentage of their respective maxima
New jobs won't use up the last slot on a minion until after a configurable delay period
Rebalance operations attempt to use the lightest valid host.
Minor changes to signatures/naming
Disable last-host-slot feature on local stack, where it will be mostly a hindrance
Attempt to simplify spawn queue slot tracking.
Additional sanity check to ensure task moves obey minion types
Minor NPE fix
Merge pull request #60 from addthis/spawn_queue

Spawn queue