minor, change date-core's dt_strfd() to converting mode too

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
cosmetics, don't overly check for sandwiches or d-onlies in dt_strfdt()

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
minor, import dconv-test.sh driver for mass conversion tests

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
minor, provide automake semantics to use dconv-test.sh as .convt test driver

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
test, provide batch conversion tests between calendars with 1-1 mapping

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
test, provide dseq batch test that the mass conversions are based upon

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
minor, rework __make_ywd()'s ABSWK_CNT converter

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
fix, convert iso-week leap years to gregorian years properly

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
major, avoid mapping yday 366 in non-leap years to 00-00 in __yday_get_md()

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
test, check built dseq and ddiff in dseq-cnt.1 test

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
minor, split up daisy converter dt_conv_to_daisy() into type-specific calls, and move them to daisy.c, ymd.c, etc.

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
fix, account for leap day rules for years beyond 2100 in daisy's __jan00_daisy() getter

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
test, provide regression for F01 and Z31 week-days from 1917 to 4095

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
fix, offset years >2100 by an equivalent year in the 1901~2100 year cycle

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
test, adapt basic_get_jan01_wday regression to recent fix

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
fix, offset by 2001 years in __jan00_daisy() to capture the leap mechanism of years 2100, 2200 and 2300

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
Merge branch 'core/conv' into next

* core/conv:
  fix, offset by 2001 years in __jan00_daisy() to capture the leap mechanism of years 2100, 2200 and 2300
  test, adapt basic_get_jan01_wday regression to recent fix
  fix, offset years >2100 by an equivalent year in the 1901~2100 year cycle
  test, provide regression for F01 and Z31 week-days from 1917 to 4095
  fix, account for leap day rules for years beyond 2100 in daisy's __jan00_daisy() getter
  minor, split up daisy converter dt_conv_to_daisy() into type-specific calls, and move them to daisy.c, ymd.c, etc.
  test, check built dseq and ddiff in dseq-cnt.1 test
  major, avoid mapping yday 366 in non-leap years to 00-00 in __yday_get_md()
  fix, convert iso-week leap years to gregorian years properly
  minor, rework __make_ywd()'s ABSWK_CNT converter
  test, provide dseq batch test that the mass conversions are based upon
  test, provide batch conversion tests between calendars with 1-1 mapping
  minor, provide automake semantics to use dconv-test.sh as .convt test driver
  minor, import dconv-test.sh driver for mass conversion tests
  cosmetics, don't overly check for sandwiches or d-onlies in dt_strfdt()
  minor, change date-core's dt_strfd() to converting mode too