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This has some cons like if you are on rev 1 which is obsolete and you do `hg up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.
-------------------------
Evolve Commands Reference
-------------------------
.. highlight:: none
amend
-----
.. hghelp:: amend
evolve
------
.. hghelp:: evolve
fold
----
.. hghelp:: fold
metaedit
--------
.. hghelp:: metaedit
next
----
.. hghelp:: next
obslog
------
.. hghelp:: obslog
pdiff
-----
.. hghelp:: pdiff
previous
--------
.. hghelp:: previous
prune
-----
.. hghelp:: prune
pstatus
-------
.. hghelp:: pstatus
split
-----
.. hghelp:: split
touch
-----
.. hghelp:: touch
uncommit
--------
.. hghelp:: uncommit