added loadModule() function.
refactored further: substituted explicit instantiation of backend proxies with a factory, wrapped configuration reading/access into a ConfigHolder class, created Logger class to wrap the logging functionality.
refactored: removed duplication
CommandRunner should use Logger.
LUN should accept ConfigHolder at initialisation to be able to bootstrap CommandRunner.
unit test for ConfigHolder.
added unit test; refactoring around logging.
minor - formatting