Work Towards Test Coverage & Housekeeping

* Changing the root directory of the run_tests.py script to included the tests written for the client as well.
* Renamed tests under the passive directory to abide by files they test.
* Removing unused PConfig class, which after a recursive grep found was no longer used and hence didn't need to be tests.
* Adding tests for the psapi and nodes classes.
* Removing pluginapi.py, which is no longer used by anything (thank the gods).
* Many PEP8 changes.