minor, implement note 2 (special expand for BYDAY in YEARLY)

Signed-off-by: Sebastian Freundt <hroptatyr@fresse.org>
hygiene, factor out number-of-days-of-month getting, into __get_ndom()

Signed-off-by: Sebastian Freundt <hroptatyr@fresse.org>
hygiene, constify more signatures

Signed-off-by: Sebastian Freundt <hroptatyr@fresse.org>
minor, implement note 2 (special expand for MONTHLY if BYMONTH is present in YEARLY)

Signed-off-by: Sebastian Freundt <hroptatyr@fresse.org>
test, provide regression test files for special expands/limits according to note 2

Signed-off-by: Sebastian Freundt <hroptatyr@fresse.org>
Merge branch 'core/evical'

* core/evical:
  test, provide regression test files for special expands/limits according to note 2
  minor, implement note 2 (special expand for MONTHLY if BYMONTH is present in YEARLY)
  hygiene, constify more signatures
  hygiene, factor out number-of-days-of-month getting, into __get_ndom()
  minor, implement note 2 (special expand for BYDAY in YEARLY)