obsdiscovery: use consistent filtering during discovery If we computed revision using an unfiltered repository, we should run the discovery unfiltered too.

evolve: make sure we don't stop after evolution of obsparent (issue5881) Before this patch, we were not handling the case when revset given by user also contain wdir parent which is obsolete. We were explicitly checking if wdir parent is obsolete, then update to its successor and return; without checking if we still have some revisions to be evolved. This patch make sure that after it update to the successor of obsolete parent it doesn't stop and continue to evolve other remaining revisions. Changes in tests/test-evolve-issue5881.t reflect the fixed behaviour.

evolve: extract "update" code into its own function This patch moves the code to a function which handles the case when wdir parent is obsolete and evolve will just update to its successor. And extraction of this to a function will also help us to fix the issue5881.