Attempt at making AccessControlHandler free of references to org.opends.server.workflowelement.localbackend package (clearly not public API).


AccessControlHandler.java:
Made the code a bit more generic by using the interfaces instead of the concrete LocalBackend*Operation classes.
I could not change them all, because methods specific to LocalBackend*Operation classes are sometimes called. Not sure how to fix that fully.

*.java:
Consequence of the changes to AccessControlHandler.