Handle asynchronous uncaught errors with domains

[rpaterson]

Fixes #155, #177, #279

[mattheworiordan]

I am using this fork, it's great, thanks @rpaterson. I am amazed that this is not merged into master given how invaluable it is. 👍

[rpaterson]

Fixed a bug with the original patch when test throws both sync and async errors.

[mreinstein]

it's a clever solution but given that domains are deprecated in node, closing this. see:

https://nodejs.org/dist/latest-v6.x/docs/api/domain.html

[rpaterson]

@mreinstein the doc you linked says:

This module is pending deprecation. Once a replacement API has been finalized,
this module will be fully deprecated. Most end users should not have cause to use
this module. Users who absolutely must have the functionality that domains provide
may rely on it for the time being but should expect to have to migrate to a different
solution in the future.

I'm all for a better solution when one becomes available, but right now domains seem to be the only practical way to solve this.

[mreinstein]

I hear ya. I just can't justify putting something into nodeunit which has stability level 0. I know it solves several issues but it just doesn't make sense to bank on an API that is definitely going away.