Scoring tests and fixes

[clusterfudge]

Addresses some components of #130, including

• Removing custom code for an itertools replacement

• Updating some docs typos

• Updating some docstrings to better reflect reality

• Fixing scoring in Intent.validate_with_tags, adding associated tests.

• Description of how to validate or test this PR ./run_tests.sh should capture new tests and linter.

• Whether you have signed a CLA (Contributor Licensing Agreement) Signed

[clusterfudge]

As for commit history, I'm actually planning to squash, so the EventEmitter commits should just fall out. I'll need to add the version bump as well.