traffic_ctl: Timeout connection to jsonrpc socket

[cmcfarlen]

I had a situation where traffic_server was unhappy but some tools were trying to run traffic_ctl. These all blocked on the connect to the jsonrpc socket and ended up with tons of traffic_ctl instances (and too many open fd errors). Could/should we add a timeout to that connect? The tool running traffic_ctl was also misbehaving, but this would be nice to have.