evolve: show unfinished information in `hg status -v` (issue5886)
`hg status -v` shows information about unfinished states or `hg status` shows it
when `commands.status.verbose=True` is set.
Before this patch, information about interrupted evolve does not show up because
evolve does not resgiters in cmdutil.STATES. This patch make sure we register
evolve related information there.
There has been an idea to unify cmdutil.unfinishedstates and cmdutil.STATES
which needs some work and the resulting state does looks a bit complicated. So
till the time we unify them, let's fix this bug by registering in
cmdutil.STATES.