Merge part of 'js/fmt-patch' for RFC2822 dates into 'sp/reflog'

Merge part of 'js/fmt-patch' for RFC2822 dates into 'sp/reflog'

An earlier patch from Shawn Pearce dependes on a change that is
only in "next".  I do not want to make this series hostage to
the yet-to-graduate js/fmt-patch branch, but let's try fixing it
by merging the early parts of the branch to see what happens.

Right now, 'sp/reflog' will not be in "next" for now, so I won't
have to regret this -- if this merge causes problem down the road
merging I can always rebuild the topic branch ;-).