Moved all filenames into the locals module, and made various other minor
refactorings.

Part of #87
Moved all filenames into the locals module, and made various other minor
refactorings.

Part of #87
Merge branch 'move_filenames_to_local' of https://github.com/nhandler/cs429 into move_filenames_to_local
Fixing bug which caused crates to spawn incorrectly.