Added mat4.js and mat4Test.html.
Added mat4.js and mat4Test.html.

Hvitnov/WebViewer,Hvitnov/WebViewer,robhawkes/WebViewer,OpenWebGlobe/WebViewer,Hvitnov/WebViewer,OpenWebGlobe/WebViewer,robhawkes/WebViewer,Hvitnov/WebViewer,robhawkes/WebViewer,OpenWebGlobe/WebViewer,OpenWebGlobe/WebViewer,robhawkes/WebViewer