Allow module file exclusion for devloader

Tools/DevLoader/BabylonLoader.js

@@ -155,6 +155,10 @@ var BABYLONDEVTOOLS;
                         if (file.indexOf('lib.d.ts') > 0) {
                             continue;
                         }
+                        // Manage exclude files.
+                        if (library.excludeFromLoader && library.excludeFromLoader.indexOf("file") > -1) {
+                            continue;
+                        }
 
                         file = file.replace('.ts', '.js');
                         file = file.replace('../', '');

Tools/Gulp/config.json

@@ -1873,6 +1873,10 @@
                     "../../serializers/src/glTF/babylon.glTFFileExporter.ts",
                     "../../serializers/src/glTF/2.0/Extensions/KHR_texture_transform.ts"
                 ],
+                "excludeFromLoader": [
+                    "../../serializers/src/glTF/2.0/babylon.glTFExporterExtension.ts",
+                    "../../serializers/src/glTF/babylon.glTFFileExporter.ts"
+                ],
                 "shaderFiles": [
                     "../../serializers/src/glTF/2.0/shaders/textureTransform.fragment.fx"
                 ],