MODE-2323 Removed the proxy layer and delta write functionality in Schematic

ModeShape's is no longer using Infinispan in ways where these pieces of functionality are useful.
Removing them should simplify the logic to represent more of what we're actually doing.
MODE-2323 Cleaned up previous commit, removed unused classes, enabled use of OPTIMISTIC or PESSIMISTIC locking
Merge pull request #1280 from rhauch/mode-2323

MODE-2323 Removed the proxy layer and delta write functionality in Schematic
MODE-2280 Created a couple of test cases for SchematicDB which show that the problem lies either with Infinispan or with our Schematic-related code.