Rename file
Remove a bunch of duplicated tests that exist in other files.

Must have had a merge issue sometime in the past.
Avoid requesting a stack trace on enqueuing. When debugging, the user can just pull the stack off the error object themselves.

This should be a performance boost. Per https://code.google.com/p/v8/wiki/JavaScriptStackTraceApi - "For efficiency stack traces are not formatted when they are captured but on demand, the first time the stack property is accessed"