Support Hadoop configuration as a classpath resource or file location in maven plugin

The CDK Maven plugin supports the specification of the Hadoop configuration as properties in the pom. It would be nice if it additionally supported a (list of) classpath resource location(s) as well as physical file location. This would support the case where Hadoop config files were in src/main/resources/ in the project, or in addition to a physical path on the machine, provided at runtime.

There's probably additional docs that need to exist to indicate the intended usage for the maven plugin (e.g. development-time iteration support, production deployment).