Adding Producers. Refactoring a bit. Improving tests etc.
Fixing bad tests
Updating aggregator to use hash of hash for the listeners, in stead of
hash of arrays. Updating documentation for new features. Improving tests.
Removing some fixed todo-notes.
Merge pull request #22 from stephan-nordnes-eriksen/adding_message_request

Adding message request, improving tests, adding message translation and refactoring event aggregator.