Issue #5. Introduce Maven plugin and script.

JVM users should target the Maven plugin.
Non JVM users have to use the script.

In both cases, it allows execution (or simulation with "dry-run"
mode) of specified changesets onto the configured Neo4j instance.
Shim inconsistent JDBC driver behaviour.

Returned nodes for remote DBs seems to be Map.
Returned nodes for local DBs seems to be Node.
Issue #5. Maven: uri->jdbcUri.