GUI-129: support ssl cert verification for eucalyptus connections

converted EucaAuthenticator to use httplib (like boto) so that we could re-use the CertValidatingHTTPSConnection boto uses for cert validation.
Use EucaAuthenticator directly instead of going through views/__init__.py:get_connection()
Because there is 1 required parameter and it can be "None". We don't care, so I pass None.