Support for timeouted connection (net.DialTimeout)

[alkuzad]

Currently net.Dial and tls.Dial allows connection to take forever, it can stuck setup of syslog service.

However net.Dial can be changed to net.DialWithTimeout and tls.Dial to tls.DialWithDialer passing net.Dialer.

[sirsean]

I like this idea.

I can see how we'd add a timeout field to Writer and use it in dialer.go to call the right net.Dial function.

I don't think we can add this without changing the signature of the srslog.Dial functions and breaking backwards compatibility, which is unfortunate.

It may be time to add a DialOptions struct to give us this flexibility, while allowing us to maintain compatibility with older code. Let me think about this. 😄