The singlefile mode needs a new copy for every record, because it modifies
it (such as changing fields to text), but the non-singlefile mode does not
need all that relatively expensive work, because it just updates the fields
and nothing else.

Conflicts:
	sw/source/uibase/dbui/dbmgr.cxx

Change-Id: If02cf8aca1d0f050ffb63cd85d5a9455afc5a6ea