phases: use revision number in analyze_remote_phases Same logic as the previous change to `new_heads`, see rationnal there. This avoids a small number of `nodes -> revs` conversion speeding thing up in the 100 milliseconds order of magnitude for the worses cases. However, the rest of the logic is noisy enough that it hardly matters for now.

  $ LANG=nonexistent LC_ALL=nonexistent LANGUAGE=nonexistent hg version -q
  Mercurial Distributed SCM (version *) (glob)