`wsgify` is a decorator used to turn a function into a WSGI
application.  The function takes a request object as the first
argument, and may take extra named arguments that match
``myframework.path_vars`` (`regexdispatch.RegexDispatch` can create
these variables).  It returns the body of the response.
It can use ``request.response`` to set headers and status, or also
return a `caller.Response` object.

Here's an example of a function::

    >>> from caller import wsgify
    >>> @wsgify
    ... def whats_my_name(req):
    ...     if req.method == 'POST':
    ...         return 'Hi %s' % req.params['name']
    ...     else:
    ...         return '''
    ...         <form action="%s" method="POST">
    ...         Your name: <input type="text" name="name">
    ...         <input type="submit"> </form>''' % req.request_url

Then we test it::

    >>> from testrunner import send_request
    >>> print send_request(whats_my_name, '/')
    200 OK
    Content-Type: text/html; charset=utf8
            <form action="http://localhost/" method="POST">
            Your name: <input type="text" name="name">
            <input type="submit"> </form>
    >>> print send_request(whats_my_name, '/', method='POST', 
    ...                    body={'name': 'Ian'})
    200 OK
    Content-Type: text/html; charset=utf8
    Hi Ian