Make the "ungunk" logic a little more robust.

demos/tunala/autoungunk.sh

@@ -4,13 +4,13 @@
 # mess has been left in the directory thanks to autoconf, automake, and their
 # friends.
 
-if test -f Makefile; then
-	make distclean
-	rm -f Makefile
-fi
-
 if test -f Makefile.plain; then
+	if test -f Makefile; then
+		make distclean
+	fi
 	mv Makefile.plain Makefile
+else
+	make clean
 fi
 
 rm -f aclocal.m4 config.* configure install-sh \