Revert "Rename polymer and cr_elements v0_8 to v1_0"

third_party/polymer/v0_8/components/iron-signals/README.md

 iron-signals
 ============
 
 `iron-signals` provides basic publish-subscribe functionality.
 
 Note: avoid using `iron-signals` whenever you can use
 a controller (parent element) to mediate communication
 instead.
 
 To send a signal, fire a custom event of type `iron-signal`, with
 a detail object containing `name` and `data` fields.
 
 ```javascript
 this.fire('iron-signal', {name: 'hello', data: null});
 ```
 
 To receive a signal, listen for `iron-signal-<name>` event on a
 `iron-signals` element.
 
 ```html
 <iron-signals on-iron-signal-hello="{{helloSignal}}">
 ```
 
 You can fire a signal event from anywhere, and all
 `iron-signals` elements will receive the event, regardless
 of where they are in DOM.