Prompt to continue when editing during rebase --interactive

On hitting an edit point in an interactive rebase, git should prompt
the user to run "git rebase --continue"

Signed-off-by: Jonathan del Strother <jon.delStrother@bestbefore.tv>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

git-rebase--interactive.sh

@@ -268,6 +268,10 @@ do_next () {
 		warn
 		warn "	git commit --amend"
 		warn
+		warn "Once you are satisfied with your changes, run"
+		warn
+		warn "	git rebase --continue"
+		warn
 		exit 0
 		;;
 	squash|s)