Added the Vue.js sample, demonstrating a simple GoJS app in the Vue.js framework.
Fixed a bug in DraggingTool.moveParts where it was incorrectly shifting Nodes when Nodes shifted by differing amounts.
Extended RotatingTool to work on link labels; the user still cannot rotate whole Links or the Link.path.
Restored behavior from 1.6 of Model.fromJson such that
linkdata.points property value is of type List. Version 1.7 had allowed
that property to remain as an Array of numbers.