Renames to make ABCs conform with naming conventions of the
standard library

Conflicts:
	orges/invoker/invoker.py
	orges/invoker/multiprocess.py
	orges/invoker/pluggable.py
	orges/invoker/simple.py
	orges/invoker/singleprocess.py
	orges/test/unit/optimizer/test_gridsearchoptimizer.py
Drop NumPy requirement to enable faster builds