Cocoa: Do mouse move and cursor update handling separate from view

We are using tracking areas for mouse move, enter/leave and cursor
update events, so we should keep handling of that out of the
"normal" event chain.

If we handle mouse moved events in the views' mouseMoved method,
we need to pass the event up the responder chain if we didn't handle it,
or we would break for example hover behavior in native WebViews,
because these do not handle mouse moved events directly in their
mouseMoved:, but only if the event wasn't handled otherwise
(arguably a bug in Web(HTML)View).
But passing the event up the responder chain is not good either, because
the QNSViews in the parent hierarchy get the event from their tracking
areas already.

Change-Id: I636a84ab1b7ef73070f81a8e33b5fa734ff4a42c
Task-number: QTBUG-26593
Reviewed-by: Morten Johan Sørvig <morten.sorvig@digia.com>
Reviewed-by: Eike Ziller <eike.ziller@digia.com>
Fix memory leaks in QFseventsFileSystemWatcherEngine

Sprinkle in some NSAutoReleasePools.

Task-number: QTBUG-38637
Change-Id: I0cb42d9d1cbcc4e9d273d0d43e4925fc02885b66
Reviewed-by: Eike Ziller <eike.ziller@digia.com>