hygiene, document deliberate fallthrough for coverity
hygiene, let coverity know about the range of d.hang in ywd dates
hygiene, fixup sunday in __ywd_get_jan01_wday() in hang fixup branch
hygiene, coverity can't calculate so help him a bit
Merge branch 'code/hygiene'

* code/hygiene:
  hygiene, coverity can't calculate so help him a bit
  hygiene, fixup sunday in __ywd_get_jan01_wday() in hang fixup branch
  hygiene, let coverity know about the range of d.hang in ywd dates
  hygiene, document deliberate fallthrough for coverity