Merge pull request #700 from RaananW/loadingScreen

Loading screen interface and implementation

Tools/Gulp/config.json

@@ -145,7 +145,8 @@
       "../../src/Cameras/babylon.stereoscopicCameras.js",
       "../../src/PostProcess/babylon.hdrRenderingPipeline.js",
       "../../src/Rendering/babylon.edgesRenderer.js",
-      "../../src/PostProcess/babylon.tonemapPostProcess.js"
+      "../../src/PostProcess/babylon.tonemapPostProcess.js",
+	  "../../src/Tools/babylon.loadingScreen.js"
     ]
   },
   "shadersDirectories": [