Apichatpong Weerasethakul’s “Frame by Frame” presentation last Friday (April 6) at the Pacific Film Archive of his lovely 2004 pain in the ass Tropical Malady didn’t provide much in the way of explanations. Armed with a DVD player remote and an unpretentious appreciation of his own film, the Thai director instead offered truckloads of tiny, personal details as reassurance that the thick-growth trail through his story is a simple one if we just let it be.