In “Darkest hour,” what Gary Oldman’s Churchill has to contend with in a time of war reminded me of what a newspaper editor does: tense negotiations, the reworking of sentences, an overarching need to get the message out, loudly and clearly. The real context of the story, the history, is, evidently, a very different one from this. In the early forties European countries were falling like dominoes as Hitler’s panzer division closed in