The gig economy. The “collaborative” model. Whatever cliché you want to use, Zipcar co-founder Robin Chase suggests that large-scale sharing has just gotten started. “This has the potential to reshape our cities in a dramatically positive way,” she predicts. To Chase, “the sharing economy” is more than just a groan-worthy trend. She’s a believer in the very real power of sharing – allowing our most valuable resources to be snapped up by anyone, anytime — and…