Add-support-for-use-of-the-system-timezone-database

Add-support-for-use-of-the-system-timezone-database

# License: MIT
# http://opensource.org/licenses/MIT

# License: MIT
# http://opensource.org/licenses/MIT

Add support for use of the system timezone database, rather
than embedding a copy.  Discussed upstream but was not desired.

History:
r21: adapt for timelib 2021.03 (in 8.1.0)
r20: adapt for timelib 2020.03 (in 8.0.10RC1)
r19: adapt for timelib 2020.02 (in 8.0.0beta2)
r18: adapt for autotool change in 7.3.3RC1
r17: adapt for timelib 2018.01 (in 7.3.2RC1)
r16: adapt for timelib 2017.06 (in 7.2.3RC1)
r15: adapt for timelib 2017.05beta7 (in 7.2.0RC1)
r14: improve check for valid tz file
r13: adapt for upstream changes to use PHP allocator
r12: adapt for upstream changes for new zic
r11: use canonical names to avoid more case sensitivity issues
     round lat/long from zone.tab towards zero per builtin db
r10: make timezone case insensitive
r9: fix another compile error without --with-system-tzdata configured (Michael Heimpold)
r8: fix compile error without --with-system-tzdata configured
r7: improve check for valid timezone id to exclude directories
r6: fix fd leak in r5, fix country code/BC flag use in
    timezone_identifiers_list() using system db,
    fix use of PECL timezonedb to override system db,
r5: reverts addition of "System/Localtime" fake tzname.
    updated for 5.3.0, parses zone.tab to pick up mapping between
    timezone name, country code and long/lat coords
r4: added "System/Localtime" tzname which uses /etc/localtime
r3: fix a crash if /usr/share/zoneinfo doesn't exist (Raphael Geissert)
r2: add filesystem trawl to set up name alias index
r1: initial revision

Gbp-Pq: Name 0007-Add-support-for-use-of-the-system-timezone-database.patch