EXCLUSIVE: Not all the indie films coveted by buyers are in Sundance. A spirited auction is going on right now for Janis, a package for the long-awaited film about iconic ’60s singer Janis Joplin. Martha Marcy May Marlene helmer Sean Durkin is directing, and Manchester By The Sea star Michelle Williams is now firmly set to play the singer. From what I hear, Amazon is squarely in the mix and hopes to stay in business with Williams as its Sundance 2016 acquisition Manchester…