Patch objpool.http to support SSL Authentication

Refs #54

The module objpool.http provides pooled connections without SSL
Authentication.
A new connection class is implemented in kamaki.clients.utils.https
The name of the class is HTTPSClientAuthConnection
The module objpool.http is patched by kamaki so that instances of
PooledHTTPConnection can provide HTTPSClientAuthConnection instances
as https connections.

Also, astakosclient is patched to use the same connection class in
case of an https connection.