Includes PHPDoc license tag in the file-level block with accompanying copyright notice.
Also added an AUTHORS file on the off chance of outside contributions
- URLs are now matched centrally against a whitelist
- %-encoded URLs are still handled correctly
- Dispatched methods now only handle one specific task
- Filler methods (e.g. versionPOST) are no longer required
- Unhandled URLs now return 501 Not Implemented rather than 404 Not Found; this removes some ambiguity in the semantics of 404
