Add tests from JSR-166 for COW data structures. Fix one bug found and add null checks to match contracts
Rename new tests so they are run as part of junit
Merge branch 'master' into ghost_protocol
Not all the tests passed, and there was actually a bug in COWNavigableSet pollFirst/pollLast
Merge pull request #338 from VoltDB/ghost_protocol

Add tests from JSR-166 for COW data structures. Fix one bug found and ad...