David Manning has been a familiar face around the Capitol for more than 40 years, yet he continues to learn something new every day.In the 1970s, Manning began working in Springfield for the office of Senate president Philip J. Rock. He then held a variety of Capitol-based positions including senior vice president of government relations at the Community Bankers Association of Illinois. In 2004, Manning went his own way and started Manning Consulting Group — a lobbying firm that represents more than a dozen clients …