A mother seeking justice for her murdered daughter causes a stir when she puts up three billboards berating the local police for failing to find the killer. Three Billboards Outside Ebbing, Missouri. I have to admit I kind of admire the courage it took for a producer to approve such an awkward title for a mainstream Hollywood film. Of course, this isn’t a blockbuster, but a bid for a more sophisticated end-of-the-year award season audience, written and directed by quirky English filmmaker Martin McDonagh, mainly known up till now for the offbeat 2008 hit-man comedy In Bruges. For this one,…