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.

#require docutils gettext

  $ $TESTDIR/check-gendoc el
  checking for parse errors