feat(@angular/cli): use and support webpack 2.4

Author: Charles Lyding

package.json

@@ -95,7 +95,7 @@
     "typescript": "~2.2.0",
     "url-loader": "^0.5.7",
     "walk-sync": "^0.3.1",
-    "webpack": "~2.3.0",
+    "webpack": "~2.4.0",
     "webpack-dev-server": "~2.4.2",
     "webpack-merge": "^2.4.0",
     "zone.js": "^0.8.4"

packages/@angular/cli/package.json

@@ -80,7 +80,7 @@
     "typescript": ">=2.0.0 <2.3.0",
     "url-loader": "^0.5.7",
     "walk-sync": "^0.3.1",
-    "webpack": "~2.3.0",
+    "webpack": "~2.4.0",
     "webpack-dev-server": "~2.4.2",
     "webpack-merge": "^2.4.0",
     "zone.js": "^0.8.4"