Close action item #27 (behavior of cell ranges that referencecells beyond limits)

I believe I have completed action item #27 (public comment #24), so it should now be closed.

The original question was  "What is the behavior of cell ranges that reference cells that are not defined in the document itself is defined?".  The quick answer is:
* If it's _inside_ the range that the application can handle, but not defined,
they are empty cells.  This was already there, but the text has been clarified.
* If it's _outside_ the range that the application can handle, then it is
calculated as an error.  Presumably, there WAS data there that is now no longer
accessible, and rather than giving incorrect answers, better to report an error.

For details, see the latest OpenFormula draft spec.

See:
http://www.oasis-open.org/apps/org/workgroup/office/members/action_item.php?action_item_id=2209

I won't be able to attend the teleconference tomorrow, sorry.  I have a conflicting meeting.

Note: I believe we can close #30 as well.  This was
"Post definition of Excel's YEARFRAC calculation to TC list or document library".
Doug Mahugh posted that information to the formula mailing list this week.
We're not done analyzing it, but certainly the posting is done.
I'm busy analyzing it, but I encourage others to also take a look and post
comments to the formula SC mailing list.

Thanks.

--- David A. Wheeler