add proper description when using a device without lock Android 4.2 and above.

git-svn-id: http://notifications-widget.googlecode.com/svn/trunk@188 21922344-3934-ee51-d6e3-fd981ce84c01
added tutorial images

git-svn-id: http://notifications-widget.googlecode.com/svn/trunk@189 21922344-3934-ee51-d6e3-fd981ce84c01