Register Final State of MPController, MPInterface, and Their Tests

I'm going to remove all of this multiprocessing infrastructure in the
next couple of commits, but I wanted to save the final state of these
components, just in case.
Remove MPController and MPInterface from Indexer, Experimenter, Subclasses

Indexer and Experimenter both require further "stuff removal," but the
subclasses needn't concern themselves with it any more.
Remove MPInterface, vis_server, and Tests
Move controllers/entropy_script.py to scripts/entropy_script.py
Remove MPController/MPInterface-specific Tests from Analyzers
Empty __init__.py in controllers/ so Python Knows It's a Module
Corrections to Indexers and Experimenters

Thanks, unit tests!
Revise run_tests.py and test_indexer.py

For once in my life, all the automated tests pass! But are there enough?