The new Ent Center for the Arts in Colorado Springs arrives with all the optimism that forward-thinking architecture can deliver. The building — monumental at 92,000 square feet and pricey at $70 million — is an investment in things real and symbolic. It will give the University of Colorado practical, state-of-the art classrooms for students endeavoring to be tomorrow’s creative class, and it will boost the Springs location to the top of the facilities hill in the state university system.