make <x-html> compatible with polymer.js version 20130816+
Upgrade polymer.js to version 20130816
upgrade json-patch to v0.3.5
upstream changes from PuppteerJS todomvc demo (https://github.com/PuppetJs/PuppeteerJs/tree/master/examples/todomvc/public)

- allow to pass an object where the parsed JSON data will be inserted
- fix event interception when working with Polymer
fix JSDoc, remove unused parameter
upgrade to the current Polymer syntax
upgrade to current Polymer version
upgrade to the current version of Handsontable
hot fix Polymer object assignment
upgrade <x-html> to current version (no longer uses @ to determine a path to loadable partial - uses / or ./ instead; fixes "forEach" problem on node list)
new public method morphUrl (closes #7)