* Default error handler now only logs traceback on 500 errors and all responses are HTML formatted.
* Tests passing.
* Ability to flag any exception object with self.quiet = True following @ashleysommer suggestion.
* Refactor HTML formatting into errorpages.py. String escapes for debug tracebacks.
* Remove extra includes
* Auto-set quiet flag also when decorator is used.
* Cleanup, make error pages (probably) HTML5-compliant and similar for debug and non-debug modes.
* Fix lookup of non-existant status codes
* No logging of 503 errors after all.
* lint