minor, assess wildcarded start/end ymd-dates and iterate month-wise or year-wise
test, provide regressions for month-wise/year-wise dseq(1)
minor, allow sandwich types for month-wise/year-wise dseq iterator
Merge branch 'tool/dseq'

* tool/dseq:
  minor, allow sandwich types for month-wise/year-wise dseq iterator
  test, provide regressions for month-wise/year-wise dseq(1)
  minor, assess wildcarded start/end ymd-dates and iterate month-wise or year-wise