On a brisk February evening in 2006, around a hundred people gathered in the venerable Koreatown watering hole HMS Bounty to pay their last respects to Los Angeles’ historic Ambassador Hotel. Despite the best efforts of the Los Angeles Conservancy , the Ambassador had been torn down — and among the speakers decrying the fate of the legendary institution that evening was Diane Keaton . Keaton, who died Saturday at 79, is of course known the world over for her on-screen credits, from “Annie Hall”