0.8.1 - update SystemClockCoroutine for compatibility with AceRoutine v0.3

• 0.8.1
  • Update SystemClockCoroutine to be compatible with
    COROUTINE_DELAY_SECONDS() API changed in AceRoutine v0.3.
  • Fix typos and grammar errors in USER_GUIDE.md and README.md.
  • Remove YearMonth abstraction in BasicZoneProcessor, saving 12 bytes
    of flash in WorldClock.

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

• 0.8
  • Handle Fri<=1 correctly in various python scripts. (#17)
  • Improve resolution of zonedb files and ZoneProcessor classes. (#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.

0.7.2 - support fixed offset RULES with '/' in FORMAT

• 0.7.2
  • Support timezones whose FORMAT contains a '/' with a fixed RULES column.
    Seems to make BasicZoneProcessor slightly smaller (20-80 bytes) and
    ExtendedZoneProcessor slightly bigger (50-100 bytes).
  • Split --granularity into --until_at_granularity and
    offset_granularity. Current zonedb files use values of 60 and 900
    respectively.

0.7.1 - replace TimeZone::printAbbrevTo() with getAbbrev()

• 0.7.1
  • Replace TimeZone::printAbbrevTo() with more
    flexible and useful TimeZone::getAbbrev().

0.7 - support DST transitions at 00:01; validate against Hinnant date library; upgrade to TZ 2019b

• 0.7
  • Change TimeZoneData to store mStdOffset and mDstOffset in units of
    one minute (instead of 15-minute increments, "code") in the off chance
    that the library supports timezones with one-minute shifts in the future.
  • Implement TimeOffset using 2 bytes (int16_t) instead of one byte
    (int8_t) to give it a resolution of one minute instead of 15 minutes.
  • Generate zoneinfo files containing AT and UNTIL timestamps with
    one-minute resolution (instead of 15-minute resolution). ZoneInfo files
    (zonedb/ and zonedbx/) remain identical in size. Flash memory
    consumption usually increases by 130 to 500 bytes, but sometimes decreases
    by 50-100 bytes. Timezones whose DST transitions occur at 00:01
    (America/Goose_Bay, America/Moncton, America/St_Johns, Asia/Gaza,
    Asia/Hebron) no longer truncate to 00:00.
  • Rename TimeOffset::forHour() to forHours() for consistency with
    forMinutes().
  • Make ExtendedZoneProcessor more memory efficient for 32-bit processors
    by packing internal fields to 4-byte boundaries.
  • Integrate C++11/14/17
    Hinnant Date library by
    creating additional tests/validation tests.
  • Upgrade zonedb and zonedbx zoneinfo files to version 2019b,
    after validating against the Hinnant date library.
  • Upgrade to pytz version 2019.2 to pickup TZ Database 2019b.

0.6.1 - add missing classes to doxygen docs

• 0.6.1
  • Create a second Jenkins continuous build pipeline file
    tests/JenskinfileUnitHost to use UnitHostDuino to run the unit tests
    natively on Linux. The entire set of unit tests builds and runs in 20
    seconds under UnixHostduino, compared to about 8 minutes for the single
    Nano environemnt, and 32 minutes against 4 boards (Nano, ESP8266, ESP32,
    SAMD21).
  • Fix Doxygen PREPROCESSOR so that it picks up classes which are enabled
    only on some environments (e.g. ESP8266, ESP32).
  • Add circuit schematics to OledClock and WorldClock examples.
  • Simplify logging::printf() used internally for debugging.
  • No functional change from 0.6.

0.6 - simplify Clock classes

• 0.6
  • Update tests to use UnixHostDuino.
  • Fix broken restore functionality in CommandLineClock. Make it work
    on Unix using UnixHostDuino. Make it work on ESP8266 and ESP32 again.
  • Update flash memory consumption numbers in zonedb/zone_infos.cpp and
    zonedbx/zone_infos.cpp.
  • Lift ace_time::common::DateStrings to just ace_time::DateStrings
    because it was the only data/time class in the common:: namespace so
    it seemed inconsistent and out of place.
  • Breaking Change Large refactoring and simplification of the
    ace_time::clock classes. Merged TimeKeeper and TimeProvider into a
    single Clock class hierarcy. Merged SystemClockSyncLoop (separate
    class) into SystemClockLoop (subclass of SystemClock) and
    SystemClockSyncCoroutine (separate class) into SystemClockCoroutine
    (subclass of SystemClock with mixin of ace_routine::Coroutine). Merged
    keepAlive() into ::loop() and ::runCoroutine() methods, so we don't
    need to worry about it separately anymore. Made SystemClockLoop use the
    non-blocking methods of Clock, making it as responsive as
    SystemClockCoroutine.
  • Add UnixClock.h which provides access to the internal Unix clock
    when using UnixHostDuino.

v0.5.2 - support ATmega2560; pack zoneinfo files to save 2.5 - 6 kB of flash

• 0.5.2
  • Create HelloZoneManager and add it to the README.md.
  • Recommend using "Arduino MKR ZERO" board or "SparkFun SAMD21 Mini
    Breakout" board for the "SAMD21 M0 Mini" boards.
  • Pack basic::ZoneInfo, extended:ZoneInfo and related structs tighter on
    32-bit processors, saving 2.5kB on the Basic zoneinfo files and 5.6kB on
    Extended zoneinfo files.
  • Pack basic::Transition and extended::Transition tighter on 32-bit
    processors, saving 20-32 bytes on BasicZoneProcessor and
    ExtendedZoneProcessor.
  • Test and support ATmega2560 AVR processor.
  • Replace all uses of Serial with SERIAL_PORT_MONITOR for compatibility
    with boards (e.g. SAMD boards) which use SerialUSB as the serial
    monitor.

0.5.1 - Support SAMD21 boards

• 0.5.1 (2019-07-24, TZ DB version 2019a, beta)
  • Add documentation about the ZoneManager into USER_GUIDE.md.
  • Move DateStrings string pointers into PROGMEM, saving 42 bytes of RAM.
  • Use SERIAL_PORT_MONITOR instead of Serial everywhere for portability
    across different Arduino boards.
  • Support SAMD21 boards except for EEPROM which SAMD21 does not support.

0.5 - ZoneManager allows dynamic creation of TimeZone

• 0.5 (2019-07-21, TB DB version 2019a, beta)
  • Remove over-engineered SystemClockHeartbeatLoop and
    SystemClockHeartbeatLoop and replace with just a call to
    SystemClock::keepAlive().
  • Remove overly complex ManualZoneProcessor and merge most of its
    functionality directly into the TimeZone using kTypeManual. We lose
    the manual abbreviations provided by ManualZoneProcessor but the
    simplification of using just the TimeZone object without an extra object
    seems worth it.
  • Add a stable zoneId to ZoneInfo that identifies a zone. It is
    formed using a hash of the fully qualified zone name. The
    tzcompiler.py generator script will detect hash collisions and create an
    alternate hash.
  • Rename old ZoneManager as the ZoneRegistrar, and
    repurpose ZoneManager as the TimeZone factory, which keeps an internal
    cache of ZoneProcessor. TimeZone objects can be dynamically bound to
    ZoneProcessor objects using createForZoneInfo(),
    createForZoneName(), `createForZoneId().
  • Add TimeZoneData data struct to allow serialization of a TimeZone object
    as a zoneId so that it can be reconstructed using
    ZoneManger::createForTimeZoneData().
  • Rename ZoneSpecifier to ZoneProcessor to describe its functionality
    better. ZoneInfo is now passed directly into the TimeZone object using
    the TimeZone::forZoneInfo() factory method, with the ZoneProcessor
    acting as a helper object.