Demo and API Docs

##<iron-jsonp-library>

Loads specified jsonp library.

Example:

<iron-jsonp-library
  library-url="https://apis.google.com/js/plusone.js?onload=%%callback%%"
  notify-event="api-load"
  library-loaded="{{loaded}}"></iron-jsonp-library>

Will emit ‘api-load’ event when loaded, and set ‘loaded’ to true

Implemented by Polymer.IronJsonpLibraryBehavior. Use it to create specific library loader elements.

##Polymer.IronJsonpLibraryBehavior

`Polymer.IronJsonpLibraryBehavior` loads a jsonp library.
Multiple components can request same library, only one copy will load.

Some libraries require a specific global function be defined.
If this is the case, specify the `callbackName` property.

You should use an HTML Import to load library dependencies
when possible instead of using this element.