Problem: Cannot easily get all the current marks.
Solution: Add getmarklist(). (Yegappan Lakshmanan, closes#6032)
cfb4b47de0
Cherry-pick the column number fix from patch v8.2.0871
because patch v8.2.0871 cannot be fully ported
without the method patches.
Co-authored-by: Peter Wolf <pwolf2310@gmail.com>