Added a fix and modified the unit tests to accomodate.

The bug report can be found here:

https://github.com/Pylons/webob/issues/84

SSL v3 (wrap_socket) blows up if the WSGI iterator yields an empty byte string. The compress function will buffer input if there isn't enough and return an empty byte string. As a result, the wrap_socket function of the ssl module will raise the following exception:

    ssl.SSLError: EOF occurred in violation of protocol as a result of zlib compression.