Upgrade handlebars to 1.3.0.

This was "npm update handlebars" followed by copying
runtime.js into the static directory and restoring the
copyright header.

(imported from commit 69d30cbfcb3b776cdfdcffa17a87704540eab76a)

node_modules/handlebars/runtime.js

@@ -0,0 +1,3 @@
+// Create a simple path alias to allow browserify to resolve
+// the runtime on a supported path.
+module.exports = require('./dist/cjs/handlebars.runtime');