A string of sawmill curtailments has buoyed lumber prices amid a flood of dismal housing data.  Interfor is the latest sawyer to announce cutbacks, citing declining wood demand in its decision to reduce fourth-quarter lumber output by 17%.  Competitors Canfor and West Fraser Timber earlier announced their own curtailments, both temporary and permanent, in British Columbia where log costs are high. A worker strike at Weyerhaeuser facilities in Oregon and Washington state that has stretched into its second month has resulted in a de facto production cut.  What's notable about Interfor's ...