Simplify how connection status inteval is configured and make server
log the solo logging option.

Includes a log at Meteor's addConnectionStatus method to log danger,
critical and recoveries triggers on user's connection status change.

 - Removed the connection-status history from the user list's gear
icon and now is opened by the connection-status button. Moderators will
render the same modal as before and viewers will only have access to their
own data.

 - Added data-savings shortcut at the connection-status modal.

 - Added websocket round-trip time.