Traditionally we tried to avoid interpreting date strings given by
the user as future dates, e.g. GIT_COMMITTER_DATE=2014-12-10 when
used early November 2014 was taken as "October 12, 2014" because it
is likely that a date in the future, December 10, is a mistake.

Loosen this and do not tiebreak by future-ness of the date when

(1) ISO-like format is used, and
(2) the string can make sense interpreted as both y-m-d and y-d-m.

* jk/approxidate-avoid-y-d-m-over-future-dates:
  approxidate: allow ISO-like dates far in the future
  pass TIME_DATE_NOW to approxidate future-check