Implement (short) aliases for standard directions.
camelCase, not separated_with_slugs.
Fix up some tests.
More general end-of-line matching for actions.
Update help text with direction aliases.
Merge branch 'master' into short-directions-2
Merge branch 'master' into short-directions-2
Merge pull request #25 from jerith/short-directions-2

Add short direction aliases (n for north, e for east, etc).