Making the testing Sqoop cascades easier

Got rid of setting MapRedHome in the Cascade
Extracting out the Database specific piece.
Providing a fixed function for data setup and cleanup
This code is all about providing a connection. Release should happen where and after the connection has been used and I don't think a test case should directly ask for a connection (we could restrict that). Specifications are expected to only use the create/setup db and cleanup functions where a DBSession is made available to them with autocommit on(loaned to them really) and closed automatically by the DB instance after use.  The around function of SqoopTestingSupport deals with this.