TigonSQL dependent on tigon-common and tigon-api; Use File instead of Location.

* Move classes dependent on Hadoop from tigon-common to tigon-core. Now tigon-sql is dependent only on tigon-common (and tigon-api).
* Use File instead of Location in tigon-sql since all operations are on local filesystem
* Cleaned up pom files because of the move above and some housekeeping
Move this inside try block you don't have to initialize to null.