Updated status code and source information

Source 1: Hypertext Transfer Protocol -- HTTP/1.1 RFC 2616 Fielding, et al.
          http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html

Source 2: http://en.wikipedia.org/wiki/List_of_HTTP_status_codes

Source of the status code and description is assumed to be Source 1 unless otherwise noted.
PEP8 two lines before class
Removed '.' from description_fail
Added formencode dependency
Added validator to 'code'

imported formencode and attached a validator to code to ensure that code is a positive integer from 100 to 599.

Changed the default 'code' to 200.
removed blank line
Added a unit_test

Unit test with 100% coverage of http_status.py
Add Chad's name to Authors, update email address, move from Beerware to BSD 2-clause