neo initialization -> small to-dos

[stevevanhooser]

Remaining TODOs:

• Reorganize the test structure, would be nice to have test utils as a single class.
• Check how we can run automated tests for all readers at the same time.
• Write more tests.
• Think of what to do with blocks & sections (probably worth leaving it up to the first person who will stumble upon multiple blocks in a file, then they will know what's the comfortable api for that; creating neo.block_and_section_to_section_index() function like we discussed is a good idea too).
• Probably override mfdaq_channeltypes, mfdaq_prefix, mfdaq_type methods to show that we only have 3 channel types with Neo ("analog_in", "event", "marker").
• allow flexible Python initialization that detects whether Python and neo are available, calls neo.insert_python_path if it is available.
• Add an ndr.neo_available function that tests whether the python interface is available and gives the user feedback about which parts are found or not found