Emma Rice's lauded version of the film returns with charm and inventiveness intactIt would be so easy to make fun of the 1945 Noel Coward/ David Lean film in which, famously, nothing happens between two guilt-ridden married lovers. That oh-so-British middle class restraint, those flet, perfectly enunciated vowels, the overwhelming romantic rush of Rachmaninov's Piano Concerto No.2 " isn't it all a bit OTT, just …