Report on push/pull if heads are merged, too, like for new heads. Use case: If a remote repo has two heads and I _want_ to merge them, I merge and push. Meanwhile someone else pushed on top of one of the heads. He won't get a warning, because he doesn't create a new head, I won't notice that I don't close a head, because I don't get a message telling me.

--- a/tests/test-push-warn.out
+++ b/tests/test-push-warn.out
@@ -47,4 +47,4 @@ searching for changes
 adding changesets
 adding manifests
 adding file changes
-added 1 changesets with 1 changes to 1 files
+added 1 changesets with 1 changes to 1 files (-1 heads)