CM-399 Removed circular dependency between Kettle Engine and Pentaho Metadata

... a class inside of kettle-engine.

Also removed a dependency on kettle-db which is no longer used.

Updated test to clean up after itself

CM-399 - Removed classes which are being relocated to the pentaho-registry commons project (to help remove circular dependency between kettle-engine and pentaho-metadata)

CM-399 - Updated the dependencies for pentaho-metadata