Bring post stats up into excerpt meta area.  [Temporarily] revert inclusion of visibility in stats.

See 48b2eab for reference.
Put "view post" link among post tools.  Revert to text link.  See 48b2eab for reference.
Reinstate "comment" link on post excerpts.

See 48b2eab for reference.
Move non-mutation tools out of span.mutation.