Inconsistent use of ISNT-ARENT

[eriktorbjorn]

Some actions use ISNT-ARENT to print either "isn't" or "aren't" depending on if it's a plural object or not, e.g.:

<DEFINE V-UNPLUG ()
	 <TELL CTHEO>
	 <ISNT-ARENT>
	 <TELL "connected to ">
	 <COND (<T? ,PRSI>
		<TELL THEI>)
	       (T
		<TELL "anything">)>
	 <ZPRINT ,PERIOD>
	 T>

Some don't, though. At the very least not V-UNTANGLE, V-FEED, and V-POUR-FROM.