The metaphors for starting over are innumerable: a snake sheds its skin, a phoenix rises from the ashes, one door shuts while another opens, everything you own’s in the box to the left. Transitions aren’t quite as clean in LVL3’s “Fantastic Facade.” Instead, the three artists at the heart of this show — Katie Bell, Hannah Carr and Jenn Smith — concern themselves with equitably negotiating the past with the future. Think evolution, not revolution…