Support multiple user sessions

[jedireza]

Currently when we create a new session, we remove any other current sessions. This can get annoying if you want to stay logged in across devices (like on your phone and on your desktop).

• The solution to this is to remove this cleaning step:
  

  frame/server/models/session.js

  Lines 52 to 60 in ee86864

  	clean: ['newSession', function (results, done) {
  	const query = {
  	userId,
  	key: { $ne: results.keyHash.hash }
  	};
  	self.deleteOne(query, done);
  	}]

• We should extend the information stored on the session records too, like the user agent, last access time, ip address, etc... GitHub has something like this in Account Settings > Security.
  • 
• We should extend the user details admin screen, listing the current sessions, with the ability to remove/revoke them.
• We should also extend the account settings page so users can manage their own sessions too.

[jedireza]

Closed via #182