Connect & Disconnect

[andymandias]

Restructures how connection/disconnection are handled, to:

• Allow users to manually connect to disconnected servers via sidebar context-menu
• Allow servers to be disconnected without triggering auto-reconnect or being removed from the sidebar
• Allow users to specify servers that should not be connected to on launch (or when added via configuration reload)

Additionally:

• Adds context-menu entry for removing servers from the sidebar
• Improves the handling of disconnect on SASL authentication failure
• Re-initiates connections when the connection details are changed as part of a configuration reload

[casperstorm]

I think we should rename Leave to Disconnect.

[casperstorm]

Follow up. I think its bit strange to see both Leave (Disconnect) and Remove.
Perhaps should consider only showing Remove when they are Disconnected.

We could also use the seperator like we have on a user context:

Connected:

ergo <-- name of server to keep it similar with user context
----
Close all queries
Mark server buffer as read
Mark entire server as read
Open in new pane
Open in new window
Replace current pane
Disconnect <--- Connect if disconnected
Remove <--- Only shown if disconnected