Gns 91- Encrypt communications to remote server

This adds authentication as well as ssl encryption to the websocket connection to remote servers.  Local servers are unaffected.

To configure a server as a remote server, add the following:

lst$ cat ~/.config/GNS3/cloud.conf
[CLOUD_SERVER]
web_username=test123
web_password=test456
ssl_enabled=yes
ssl_crt=/home/jseutterlst/.config/GNS3Certs/localhost.crt
ssl_key=/home/jseutterlst/.config/GNS3Certs/localhost.key

.. and run "./create_cert.sh localhost" in gns3server/cert_utils/ in the gns3server codebase to generate the certs.

The code is currently unreachable until we have some more plumbing code implemented.