Move scratch-storage init/attach to vmListenerHOC

Attaching the storage module in `vmListenerHOC` means it can propagate
down to the GUI, stage, and blocks naturally. The default VM property
value has been removed from those places so that we're not instantiating
extra VM instances any more. Instead, using one of those components
outside of the `vmListenerHOC` framework will require providing a VM
instance as a property.

src/components/gui/gui.jsx

@@ -11,8 +11,6 @@ const MenuBar = require('../menu-bar/menu-bar.jsx');
 const Box = require('../box/box.jsx');
 const styles = require('./gui.css');
 
-const Storage = require('../../lib/storage');
-
 const GUIComponent = props => {
     const {
         basePath,
@@ -72,12 +70,9 @@ const GUIComponent = props => {
 GUIComponent.propTypes = {
     basePath: React.PropTypes.string,
     children: React.PropTypes.node,
-    vm: React.PropTypes.instanceOf(VM)
+    vm: React.PropTypes.instanceOf(VM).isRequired
 };
 GUIComponent.defaultProps = {
-    basePath: '/',
-    vm: new VM(),
-    storage: new Storage()
+    basePath: '/'
 };
-GUIComponent.defaultProps.vm.attachStorage(GUIComponent.defaultProps.storage);
 module.exports = GUIComponent;

src/containers/blocks.jsx

@@ -159,7 +159,7 @@ Blocks.propTypes = {
             dragShadowOpacity: React.PropTypes.number
         })
     }),
-    vm: React.PropTypes.instanceOf(VM)
+    vm: React.PropTypes.instanceOf(VM).isRequired
 };
 
 Blocks.defaultOptions = {
@@ -188,8 +188,7 @@ Blocks.defaultOptions = {
 };
 
 Blocks.defaultProps = {
-    options: Blocks.defaultOptions,
-    vm: new VM()
+    options: Blocks.defaultOptions
 };
 
 module.exports = Blocks;

src/containers/stage.jsx

@@ -175,11 +175,7 @@ class Stage extends React.Component {
 }
 
 Stage.propTypes = {
-    vm: React.PropTypes.instanceOf(VM)
-};
-
-Stage.defaultProps = {
-    vm: new VM()
+    vm: React.PropTypes.instanceOf(VM).isRequired
 };
 
 module.exports = Stage;

src/lib/vm-listener-hoc.jsx

@@ -2,6 +2,8 @@ const bindAll = require('lodash.bindall');
 const React = require('react');
 const VM = require('scratch-vm');
 
+const Storage = require('./storage');
+
 const {connect} = require('react-redux');
 
 const targets = require('../reducers/targets');
@@ -89,9 +91,11 @@ const vmListenerHOC = function (WrappedComponent) {
         onTargetsUpdate: React.PropTypes.func,
         vm: React.PropTypes.instanceOf(VM).isRequired
     };
+    const defaultVM = new VM('vm-listener-hoc');
+    defaultVM.attachStorage(new Storage());
     VMListener.defaultProps = {
         attachKeyboardEvents: true,
-        vm: new VM()
+        vm: defaultVM
     };
     const mapStateToProps = () => ({});
     const mapDispatchToProps = dispatch => ({