[WFLY-2052] / [WFLY-490] Inform user whey they are not being prompted for a realm if it is either supplied on the command line or it was discovered from the property files.
[WFLY-743] Protect against NullPointerException introduced by this change.
[WFLY-490] Guard against bogus attributes in the resource description

Conflicts:
	controller/src/main/java/org/jboss/as/controller/operations/global/ReadResourceDescriptionHandler.java