The libraries in Delaware County, Pa., are trying to shift into warp speed. The county is hooking eight branches to a fiber-optic network to help meet library patrons’ ever-rising demand for high-bandwidth tasks like streaming educational videos and uploading online resumes. Yet that still leaves 17 of the county’s branches in the digital slow lane. Jacking just the eight libraries into fiber lines is costing about $200,000 this year, a big chunk of the system’s budget. So the other branches have to wait.