0.8 - support 1-minute resolution for all Extended timezones and most Basic timezones

[bxparks]

• 0.8
  • Handle Fri<=1 correctly in various python scripts. (correctly handle Fri<=1 expressions in TZ database #17)
  • Improve resolution of zonedb files and ZoneProcessor classes. (improve STDOFF and DST offsets to handle one minute resolution  #18)
    • Both BasicZoneProcessor and ExtendedZoneProcessor support 1-minute
      resolutions for the AT and UNTIL fields.
    • BasicZoneProcessor (and zonedb files) support a 15-minute resolution
      for both STDOFF and DST offset fields.
    • ExtendedZoneProcessor (and zonedbx files) support one-minute
      resolution for STDOFF field and 15-minute resolution for DST offset
      (with a range of -01:00 to 02:45). (4 bits of the deltaCode
      field were given to the offsetCode field to give it the
      1-minute resolution.)
    • Regenerate zonedbx using 1-minute resolution.
  • Fix broken BasicZoneProcessor on some timezones between 1975 and
    2000. Did not handle transitions from fixed ZoneEra (RULES='-') to named
    ZoneEra (RULES=reference) or vise versa. Verified against pytz and
    Hinnant date from 1975 to 2050.