Difficult to use for arbitrary URLs

piston_mini_client is great for implementing multiple methods against a single service. However, there are cases where we want to do almost everything that piston_mini_client does, but without the service_root + '/' + path logic: we just want to hit a URL with some method and some data.

To do that at the moment, one has to write something like this::

    class SingleURLAPI(PistonAPI):

        def __init__(self, url, auth=None, disable_ssl_validation=False,
                     log_filename=None, timeout=None):
            super(SingleURLAPI, self).__init__(
                service_root=url, cachedir=None, auth=auth,
                disable_ssl_validation=disable_ssl_validation,
                log_filename=log_filename, timeout=timeout)

        def _path2url(self, path, scheme):
            # We don't want the service_root + '/' + path behaviour.
            return self._service_root

        def put(self, data):
            return self._put(None, data)

I suggest that piston_mini_client extracts most of PistonAPI into a separate class, say PistonRequest, that implements public methods for each request method type and does what _put, _get, etc. do now. Then PistonAPI can be a class intended to be subclassed for API definitions.