This is the second public release of httpy, incorporating the following
significant API changes in addition to miscellaneous bug fixes:

  - Since Response objects represent both success and error conditions,
    responders may now return a Response object, not just raise one. This is
    not strictly enforced, however (i.e., you can still raise Response(200)),
    because the alternative -- mapping HTTP response categories to Python
    success/error conditions -- is overly complicated.

  - The module hierarchy is now more deeply nested to avoid importing unused
    modules.

  - Response headers may now be specified as a list of 2-tuples or a
    dictionary; either are converted to an email.Message.Message object by the
    constructor.

  - httpy now logs to stdout in the Combined Log Format, and to stderr in a
    custom error format.


Also note that we have tweaked the versioning scheme, and 0.9.0 should now be
considered equivalent to an 0.9a1 version. Depending upon public interest and
feedback, there may be one or two more alpha releases in which the API may
change significantly, followed by one or two beta releases, a release candidate,
and then a final release, which will be called 0.9.1.