Feature timeout handler

[jbrumwell]

Adds the ability to use a custom timeout handler, currently we expose TimeoutError but no way to inherit from it and apply it to callbacks as a handler.

[jmar777]

Thanks for all the pull requests today! I haven't had a chance to review them, but I'll dig into them soon!

[jbrumwell]

No problem, I stumbled upon candle and loved what it offered but the api was not how I'd have designed it. Then found cb which is my preferred api and wanted to add the missing functions so I thought I'd spend a couple of hours and add them.

There is still one thing I feel like is missing, which is the ability to restart the timeout, on timeout for a type of interval timeout.

If I get some time today I may add it

[anhldbk]

@jmar777 ping ping ping