* Test runner: Detect extra property in 'actual' but not in 'expected'.
Also update all expected.json where this would result in errors.
* Include rmExpected.js script in case it is needed again
Expanding on #150, this allows `unexpected()` to accept the expected token type instead of a message string.
This overload is then used in a couple more places (that independently implement a logic similar to `expect()`'s) to construct an `Unexpected token, expected FOO` message.
* This removes the exponentiationOperator as it is now in es2016
* Remove from tests
* Remove asyncFunctions and restructure test dirs
* Remove trailingFunctionCommas
