remove unused class (testing how to flatten a json)
Cleaning and documenting tests

- Added javadoc to each test
- Split Redis test in two, basic string, and hmset
- Renamed DatastoreRemoteThreadedTest2 to
DatastoreRemoteBatchThreadedTest, in order to show that it uses batch
inserts on the server side
- Added instructions to Mysql and SQLServer (the must have a schema,
table and user to connect)