Merge branch 'jc/fmt-merge-msg-people'

Tone down the lines that credit people involved and make them
comments, so that integrators who edit their merge messages can
still make use of the information, but lazy ones will not leave
the unverified guesses placed on the "via" line.

* jc/fmt-merge-msg-people:
  fmt-merge-msg: make attribution into comment lines

diff --cc builtin/fmt-merge-msg.c
Simple merge