Hi Dimitris,
We faced the same issue.
The reason for the removal in newest version is described here:
SVG Working Group Teleconference -- 24 Aug 2015
JointJS Team posted this polyfill:
SVGElement.prototype.getTransformToElement = SVGElement.prototype.getTransformToElement || function(elem) { return elem.getScreenCTM().inverse().multiply(this.getScreenCTM()); };
Place this code into your 'onInit' function of the 'Main' controller.
Cheers,
Pavel