Reap/Close old connections when max connection count is hit

[jbpratt]

Due to firefox tabs continually crashing on me, I quickly hit the 5 connection count cap (https://github.com/destinygg/chat/blob/master/connection.go#L138).

Rather than outright rejecting new connections, would it make sense to close old connections (resetting to 0) and allowing new connections?

I'd be perfectly willing to put in a patch/PR should anyone have any input on this.

ian@home ~ $ netstat | awk '/destiny/'
tcp        0      0 192.168.1.4:53654       destiny.gg:https        ESTABLISHED
tcp        0      0 192.168.1.4:54422       destiny.gg:https        ESTABLISHED
tcp        0      0 192.168.1.4:54232       destiny.gg:https        ESTABLISHED
tcp        0      0 192.168.1.4:54588       destiny.gg:https        ESTABLISHED
tcp        0      0 192.168.1.4:53466       destiny.gg:https        ESTABLISHED

I believe @SoMuchForSubtlety is having this issue