Hover: dismiss to left remove from all (status bar and notif drawer) and from right only from hover

Partialy ported from SlimKat Heads up idea with a huge thanks to @kufikugel.
A boolean is used to determine the dismiss direction and further dismiss the notification completely or only from hover.

Change-Id: Iba7c1841ffaec360d204dc3326f24e91fa1a4310