Fix new lint errors

We'll get to lint parity soon and then not need to do this.

Author: zpao

src/browser/ui/React.js

@@ -9,6 +9,8 @@
  * @providesModule React
  */
 
+/* globals __REACT_DEVTOOLS_GLOBAL_HOOK__*/
+
 "use strict";
 
 var DOMPropertyOperations = require('DOMPropertyOperations');

src/browser/ui/ReactMount.js

@@ -764,7 +764,7 @@ var ReactMount = {
           'methods are impure. React cannot handle this case due to ' +
           'cross-browser quirks by rendering at the document root. You ' +
           'should look for environment dependent code in your components ' +
-          'and ensure the props are the same client and server side:\n' +
+          'and ensure the props are the same client and server side:\n%s',
           difference
         );
 

src/core/ReactCompositeComponent.js

@@ -611,8 +611,8 @@ var ReactCompositeComponentMixin = assign({},
         displayName
       );
     } else {
-      for (key in parentKeys) {
-        var key = parentKeys[key];
+      for (var i = 0; i < parentKeys.length; i++) {
+        var key = parentKeys[i];
         warning(
           ownerBasedContext[key] === parentBasedContext[key],
           'owner-based and parent-based contexts differ '  +

src/core/__tests__/ReactCompositeComponent-test.js

@@ -1060,7 +1060,7 @@ describe('ReactCompositeComponent', function() {
     });
 
     var component = React.withContext({foo: 'noise'}, function() {
-      return <Component />
+      return <Component />;
     });
 
     ReactTestUtils.renderIntoDocument(<Parent>{component}</Parent>);

src/test/ReactTestUtils.js

@@ -321,7 +321,7 @@ ReactShallowRenderer.prototype.getRenderOutput = function() {
 
 var ShallowComponentWrapper = function(inst) {
   this._instance = inst;
-}
+};
 assign(
   ShallowComponentWrapper.prototype,
   ReactCompositeComponent.ShallowMixin