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
Personally I am beginning to prefer that we avoid referring to tuple fields using the `_i` field names. Can we use pattern matching instead?  (I know that's a bit of a pain in this particular situation.)

This comes from seeing user code where people save some arbitrary combination of data in a tuple, and refer to the fields by their `_i` names in other bits of code without worrying about how readable that is. I would like to start discouraging such code in code reviews, and I think we should lead by example in maestro.

But this is very much a personal opinion and I'm open to you not agreeing with me!