The two functions ME_FindItemAtOffset and ME_RunOfsFromCharOfs were almost
identically used, since ME_FindItemAtOffset was always used to find a run.
The only difference was how they returned the offset within the run for an
end of paragraph run.

For ME_FindItemAtOffset it would return the next run if it was in between \r
and \n. ME_RunOfsFromCharOfs would instead return an nOffset of 0 for end
paragraph runs.  This subtle difference introduced bugs, so I decided to
avoid having special case in this function when creating this patch, and
instead let the caller handle this case.