updated Viewer.prototype._onDataSourceAdded to add the 
emovalFunc first, which seems to fix the bug
updated Viewer.prototype._onDataSourceAdded to add the 
emovalFunc first, which seems to fix the bug

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