Issue #1804592 by a.ross, andyg5000, mglaman, czigor, roderik, rooby,...

Issue #1804592 by a.ross, andyg5000, mglaman, czigor, roderik, rooby, torgosPizza, Anybody, GoZ: reload an up to date copy of the order being processed through a checkout form during Ajax related form rebuilds and related scenarios to avoid resaving old revisions.