Issue #12. Add DryRunMode/RunMode support

Users can now select either DRY-RUN or RUN.
As for Liquibase, DRY-RUN prints to file the statements that would
be executed if configured to RUN mode.

Also significantly augmented test coverage.
Issue #15. Allow GraphDatabaseService direct conf

This now allows users to specify a full-fledged embedded graph
database, thus avoiding directory locking issues.
Issue #5. Introduce Maven plugin and CLI.
Issue #5. Append JAR to releasable script.