Fix ES5 issues

Author: vidartf

js/scripts/prop-types.js

@@ -66,9 +66,9 @@ class ThreeType extends BaseType {
     getTraitlet() {
         let typeName = this.typeName;
         if (typeName instanceof Array) {
-            for (let tname of typeName) {
+            typeName = typeName.map(tname => {
                 return `${tname || 'ThreeWidget'}`;
-            }
+            });
         } else {
             typeName = `${typeName || 'ThreeWidget'}`;
         }

js/src/core/BufferGeometry.js

@@ -65,7 +65,7 @@ var BufferGeometryModel = AutogenBufferGeometryModel.extend({
                 return createModel(modelCtor, this.widget_manager, kv[1]).then(function(model) {
                     return [kv[0], model];
                 });
-            }));
+            }, this));
         }).then(function(attribModelKVs) {
             toSet.attributes = _.object(attribModelKVs);
 
@@ -75,7 +75,7 @@ var BufferGeometryModel = AutogenBufferGeometryModel.extend({
                 var modelCtor = kv[1].isInterleavedBufferAttribute ? InterleavedBufferAttributeModel : BufferAttributeModel;
                 return createModel(modelCtor, this.widget_manager, kv[1]).then(function(model) {
                     return [kv[0], model];
-                });
+                }, this);
             }));
         }).then(function(attribModelKVs) {
             toSet.morphAttributes = _.object(attribModelKVs);