SLING-4268 - ContentLoader should not try to import ACLs

Skip nodes named rep:policy when importing. This is not 100% full-proof
( looking at the node's primary type would be ideal ) but will work for
all practical cases.

git-svn-id: https://svn.apache.org/repos/asf/sling/trunk@1648266 13f79535-47bb-0310-9956-ffa450edef68