Add support for the newly announced enhanced link profile code

Title says it all.

Add support for the newly announced enhanced link profile code. I could manually add this, but I assume you would want to add it to the core.

https://support.google.com/analytics/bin/answer.py?hl=en&answer=2558867

Thanks

https://www.ads-software.com/extend/plugins/google-analytics-for-wordpress/