Merge branch '170424' of github.com:jwpi/util-linux

* '170424' of github.com:jwpi/util-linux:
  parse-date: time_zone_hhmm() bug fixes
  parse-date: remove unused ordinal_day_seen
  parse-date: remove unused year_seen
  parse-date: refactor tm_diff()
  parse-date: use to_uchar() instead of assignment.
  parse-date: use uintmax_t where appropriate
  parse-date: use int where appropriate
  parse-date: use intmax_t where appropriate
  parse-date: remove unused EPOCH_YEAR
  parse-date: replace ISDIGIT with c_isdigit