API change: addNode() now accepts string or Node
API change: addNode() now accepts string or Node

dabobert/springy,dabobert/springy,dhotson/springy,kidylee/springy,tigerleapgorge/springy,drstarry/springy,tigerleapgorge/springy,shigeruNakajima/springy,kidylee/springy,pingjiang/springy,dhotson/springy,pingjiang/springy,shigeruNakajima/springy