The required protocol version check occurs before the consensus flavour
check. So on directory mirrors (and some client configs), alpha users need
to delete both consensus flavours to workaround nss bugs.

Closes ticket 27756.

Forward-ports fix for 27488.

Remove the "documentation" section, since a comment-only change
doesn't usually get a changelog entry.

(it came out before 0.3.2.10, because 0.3.2.10 has backports from it)

   "We fray into the future, rarely wrought
     save in the tapestries of afterthought"
       -- Richard Wilbur, _Years End_