Extend the check for webkit prefixed pointer props
Extend the check for webkit prefixed pointer props

 + webkitRadiusX/Y
 + webkitRotationAngle

Re: #279

taye/interact.js,adamgruber/interact.js,Endika/interact.js,mcanthony/interact.js,bios21/interact.js,mcanthony/interact.js,Endika/interact.js,marian-r/interact.js,marian-r/interact.js,bios21/interact.js,adamgruber/interact.js,taye/interact.js,taye/interact.js