SLING-3308 Upgrade to Rhino 1.7R4

Apply extended patch by Rohit Kumar (Thanks alot !). Extensions to
the original patch are checking all wrapper objects whether the
wrapped field needs a null check.

git-svn-id: https://svn.apache.org/repos/asf/sling/trunk@1557909 13f79535-47bb-0310-9956-ffa450edef68