The library at Rowen Elementary School is musty and outdated – a locked room used for storage and occasional meetings, a repository of yellowing, untouched books, the Philadelphia Inquirer reports. But Callie Hammond has big dreams for the room, whose leather-bound encyclopedias were printed in 1986, the year she was born. Hammond sees the West Oak Lane public school as a launching pad for Library Build, a nonprofit group she recently started to renovate and staff school libraries with fellows in the Teach for America model…