v3.2.0. Improvement.

- v3.2.0 August 19, 2013
	- Wrapped Task execution in a domain to catch uncaught errors within
the task execution, as well as added checks to ensure the completion
callback does not fire multiple times
		- These will be reported via the `error` event that the Task will emit
			- If the Task is part of a TaskGroup, the TaskGroup will listen for
this, kill the TaskGroup and emit an `error` event on the TaskGroup
	- Moved from EventEmitter2 to node's own EventEmitter to ensure domain
compatibility