THE FINAL GIRLS **** USA 2015 Dir: Todd Strauss-Schulson. 88 mins A wonderfully warm and witty high-concept homage to 80’s slasher movies, opening with a mock trailer for CAMP BLOODBATH, complete with “ki-ki-ma-ma” pastiche and an ominous voiceover intoning “They won’t be singing Kum Ba Ya, they’ll be singing Kum…