* Add support for setting alias when creatign instance.
The POST to create a instance now provides an `alias` field which
then can be used to access the instance services through the following
URL:
`http://<alias>-<short_session>-<port>.<tld>`
When creating a session you can now send an `alias`
* Remove unnecessary function
* Add alias support for DNS resolution
It fixes lots of bugs, can fallback to long polling, resize viewport of
terminals and share clients state of the session, so they all see the
same thing.
