This patch is a follow up to an out of scope comment made by R. David Murray in #20898 (http://bugs.python.org/issue20898#msg213771).

In a nutshell, there is some redundancy between http.client and http.server insofar as the definition of http status code, names and descriptions go. The included patch is a stab at cleaning some of this up while remaining backwards compatible and is intended to solicit feedback before finishing work.

TODOs:
* Populate descriptions for status codes
* Documentation
* Tests (?)