0.9.3.38: further fixes to ENCODE- and DECODE-UNIVERSAL-TIME:

0.9.3.38: further fixes to ENCODE- and DECODE-UNIVERSAL-TIME:
* DECODE-UNIVERSAL-TIME now calls out to UNIX time functions to obtain
  daylight savings time and timezone information for the entire range
  of 32-bit time_t, and when below that calls with a plausable date in
  1903.
* ENCODE-UNIVERSAL-TIME now no longer errors when passed a decoded
  time with a year in 1899, so long as the encoded time is
  non-negative.