[DOC beta] Add yui doc @since tags to methods and properties added after...

... 1.0.0

This will cause an "Available since" line on the api doc site next to these methods/properties.
![screen shot 2014-04-10 at 12 46 07 pm](https://cloud.githubusercontent.com/assets/54056/2670844/e2fd5de4-c0d2-11e3-8d03-84784597d39d.png)