Adds proper kDOP distanceToCamera function (3D)
Adds proper kDOP distanceToCamera function (3D)

likangning93/cesium,CesiumGS/cesium,AnalyticalGraphicsInc/cesium,likangning93/cesium,CesiumGS/cesium,CesiumGS/cesium,CesiumGS/cesium,likangning93/cesium,CesiumGS/cesium,AnalyticalGraphicsInc/cesium,likangning93/cesium,likangning93/cesium