evolve: don't show working directory obsolete message if we were on it This patch tweaks showing wc obsolete message functionality to not show the message if the operation led us to the same changeset we were on before and it didn't obsoleted it. This make failed updates, update on current changeset and a pull with no change omit showing the message. This has some cons like if you are on rev 1 which is obsolete and you do `hg up <revset>` where revset is some revset which resolves to the rev 1, we won't show the warning as shown earlier.