test, add regression tests for bug 22

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
minor, provide daisy specific getters for wcnt, wcnt_iso and wcnt_abs

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
minor, implement the path for daisy->wcnt in dt_get_wcnt_year()

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
Merge branch 'bug/22'

* bug/22:
  minor, implement the path for daisy->wcnt in dt_get_wcnt_year()
  minor, provide daisy specific getters for wcnt, wcnt_iso and wcnt_abs
  test, add regression tests for bug 22
minor, introduce yd helper struct

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
minor, move iso-week and week-of-year related calculations to yd.c

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
minor, provide __X_to_yd() converters and dt_conv_to_yd()

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
minor, rewrite dt_get_wcnt_year() in terms of yd objects

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
minor, rid chucked-in __X_get_wcnt*() routines for X = ymd and daisy

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
hygiene, forward decl dt_conv_to_yd() outside of dt_get_wcnt_year()

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
hygiene, support compilers without anonymous struct initialisation for __X_to_yd()

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
Merge branch 'code/hygiene'

* code/hygiene:
  hygiene, support compilers without anonymous struct initialisation for __X_to_yd()
  hygiene, forward decl dt_conv_to_yd() outside of dt_get_wcnt_year()
  minor, rid chucked-in __X_get_wcnt*() routines for X = ymd and daisy
  minor, rewrite dt_get_wcnt_year() in terms of yd objects
  minor, provide __X_to_yd() converters and dt_conv_to_yd()
  minor, move iso-week and week-of-year related calculations to yd.c
  minor, introduce yd helper struct