AuthN Plugin Response Handling

[ashcrow]

Authentication plugins can now directly handle the HTTP response body, headers, and code directly if wanted. To handle the responses within the plugin start_response must be called and a list (the response body) must be returned. If the plugin wants to allow the plugin system to handle the rejection the plugin should continue to return True on success and False on failed authentication.

Example:

def authenticate(self, environ, start_response):
    start_response('200 OK', [('content-type', 'text/plain')])
       return [bytes('example', 'utf8')]

May help for #31

[ashcrow]

(3) [multi-host-mgr-2] Allow authn plugins to provide specific status codes

[ashcrow]

@cooktheryan force pushed the spelling mistake.

[ashcrow]

@cooktheryan rebasing now.

[ashcrow]

@cooktheryan rebased. :arrow_up: