RecentChange: deprecate newFromCurRow and loadFromCurRow

This is ancient code related to the no-longer existing cur table,
which doesn't seem to be fully correct anymore and is only called
from the (deprecated) Oversight extension.

Change-Id: I0b40e3fb17ec670c5c85c8ee0dd2e8b74d72e548
Merge "RecentChange: deprecate newFromCurRow and loadFromCurRow"