Event: Only attach events to objects that accept data - for real

Event: Only attach events to objects that accept data - for real

There was a check in jQuery.event.add that was supposed to make it a noop
for objects that don't accept data like text or comment nodes. The problem was
the check was incorrect: it assumed `dataPriv.get( elem )` returns a falsy
value for an `elem` that doesn't accept data but that's not the case - we get
an empty object then. The check was changed to use `acceptData` directly.

(cherry picked from d5c505e35d8c74ce8e9d99731a1a7eab0e0d911c)

Fixes gh-4397
Closes gh-4558