Remove pointless returns

remnants of coffeescript
Stop overwriting native EventEmitter.listeners

Introduced in ce7ef43cbbf193c95fdc3b4d41fb16f4760efdd9, caused
unexpected behavior such as being unable to call
`watcher.listeners(‘add’)`

All the other extension of this listeners object (keeping track of
listeners per file) should continue to work as expected
typo
Make fsevents mode the mac default again
Improve close test
Run tests in different modes
Fix options handling
Remove extraneous args
Remove skipped test

The prior test already checks for a single add event
Refactor options test group
Clean up setup code