PHILADELPHIA — Pennsylvania’s state university system can proceed with plans to merge six of its 14 universities into two new entities under a decision announced Tuesday by its accrediting body. The Middle States Commission on Higher Education announced on its website the decision, which was one of the last significant hurdles for the plan to clear, though schools continue to wait for word from the National Collegiate Athletic Association on whether each of the six campuses can maintain their individual sports teams. Under the plan, Bloomsburg, Mansfield and Lock Haven universities in North Ce…