Updates all parts modified since last update of search index. This method should be called after parts are added or modified. Otherwise in result set of full text search, newly added parts are missing. Note: that is not a blank-recreate-complete-index function, what's done on the Extra-updateSearchIndex button in partsmanagement GUI. This method needs to be called explicitly. It is not called automatically by other methods. Multiple calls of this method should be enclosed by MDPartsDatabaseTransaction block to speed up execution time.
