Big structure change plus checks for QAV bandwidth.

Moved the test definitions to a configs sub-folder. Added the actions, graph, state_rendering and path_setup modules to try to keep the code clean.
Remove the explicit use of state functions.
Add the extra arguments to actions.py required by restructuring.
Add action_discover and action_link_down.

The paths from the controller are known so that the currently visible nodes from the controller can be determined.
Remove direct access to global variable.
Adding test for discover command
Merge pull request #15 from pthedinger/master

Big structure change plus checks for QAV bandwidth.