Cleanup

Some cleanups.

- Removed executable bits
- Changed module names to under_scores
- Renamed `blockID` module to `blocks`. I think `from blocks import WOOD` is the most natural way to import a wooden block. An alternative would be `block_ids`. What do you think?
- PEP8 cleanup
This module and it's import in `minecraft.py` can go away, we removed the need for it on the sprint day and I forgot to remove it then (sorry!).