largefiles: get function to write status messages via "getstatuswriter()" This patch makes "updatelfiles()" get appropriate function to write largefiles specific status messages via "getstatuswriter()". This patch introduces None as "print messages if needed", because True (forcibly writing) and False (forcibly ignoring) are already used for "printmessage" of "updatelfiles". Subsequent patch will move "avoid printing messages only while automated committing" decision from caller of "updatelfiles()" into "getstatuswriter()".