Freeze event objects to prevent tampering. Closes #278
Added standardized event schema for payloads. Closes #251
Updated README with schema information.
Removed unused functions.
Merge pull request #283 from arb/event-objects

Event objects
Merge from upstream.
Cleanup after merge.
Merge pull request #280 from arb/freeze

Freeze event objects to prevent tampering
Added 'request' event to listen for request.log. Closes #190