more patches to cron scripts - all date subtractions performed on a new time_now() object in ScriptHelpers::date_subtract(), NOT on the local object in case it's used again after the DT subtract() function performed
amended all cron scripts which used DateTime directly to use L::Local::Utils::time_now() instead, so time calculated correctly at day rollover (ie considers BST); patched Utils::time_now() to accept args for DT constructor (eg formatter)
moved search term highlighting in referral resource finder to a callback so html is escaped first, then search term highlighted; speeded up Excel file search in L::Local::ExcelHandler::_read_file() using add_trigger()