Refactored time management for Titan. Timepoint now has a reference to the TimestampProvider it was derived from. The serializers were removed and a default constructor added so that serialization is no longer tied to Kryo. Timepoint was refactored into an interface and some convenience methods added.
In transaction configuration, there is a transaction start time and a commit time - the latter being configurable.
Re-added ConsistentKeyLockerTest which is the only failing test case. NEED TO FIX.
Merge branch 'timestamps2' into titan05
Merge branch 'titan05' of github.com:thinkaurelius/titan into titan05
Fix ConsistentKeyLockerTest
Merge branch 'titan05' of github.com:thinkaurelius/titan into titan05