Add missing HTTP status codes taken from

Add missing HTTP status codes taken from

http://www.iana.org/assignments/http-status-codes/http-status-codes.xml

The new codes are now known and some canned error
strings are provided. The web server does not yet actually
produce them in responses or reacts on getting them
from an origin server when acting as a proxy or gateway.

Backport of r1361784, r1361791 and 1362020 from trunk.

Submitted by: rjung
Reviewed by: jorton, trawick

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1363802 13f79535-47bb-0310-9956-ffa450edef68