npm_modules: Fork bower_components into Polymer 0.4.0 and 0.5.0 versions

polymer_0.5.0/bower_components/webcomponentsjs/README.md

+webcomponents.js
+================
+
+A suite of polyfills supporting the [Web Components](http://webcomponents.org) specs:
+
+**Custom Elements**: allows authors to define their own custom tags ([spec](https://w3c.github.io/webcomponents/spec/custom/)).
+
+**HTML Imports**: a way to include and reuse HTML documents via other HTML documents ([spec](https://w3c.github.io/webcomponents/spec/imports/)).
+
+**Shadow DOM**: provides encapsulation by hiding DOM subtrees under shadow roots ([spec](https://w3c.github.io/webcomponents/spec/shadow/)).
+
+This also folds in polyfills for `MutationObserver` and `WeakMap`.
+
+
+## Releases
+
+Pre-built (concatenated & minified) versions of the polyfills are maintained in the [tagged versions](https://github.com/webcomponents/webcomponentsjs/releases) of this repo. There are two variants:
+
+`webcomponents.js` includes all of the polyfills.
+
+`webcomponents-lite.js` includes all polyfills except for shadow DOM.
+
+
+### Manually Building
+
+If you wish to build the polyfills yourself, you'll need `node` and `gulp` on your system:
+
+ * install [node.js](http://nodejs.org/) using the instructions on their website
+ * use `npm` to install [gulp.js](http://gulpjs.com/): `npm install -g gulp`
+
+Now you are ready to build the polyfills with:
+
+    # install dependencies
+    npm install
+    # build
+    gulp build
+
+The builds will be placed into the `dist/` directory.
+
+## Contribute
+
+See the [contributing guide](CONTRIBUTING.md)
+
+