Peers: added tags while editing.
Peers: added tags on new peer creation.
Users: improved some behaviors while editing the aliases.
Peers: tags are not shown when asked for public peers.
References: peer tags are added to the new reference cloned from a peer.
Authentication: solved the double login problem.
System status: add an api to get the system status.
Authentication: added start page. If there are no users the start page is presented instead of the login page.
Authentication: start page disabled when there are users in the system.
Start page: centered and enlarged the start button.