GoogleAnalytics.Current.EnableDisplayFeatures() is messy when you want to enable it for the whole site..

David, 

Unfortunately, our use-case for the 'DisplayFeatures' tag is to have it set up on every page.
It would be neater if we could just set a "Enable this feature site wide" flag for our use case.

Using the GoogleAnalytics.Current.EnableDisplayFeatures method for this means that we have to enable it for every request,  which is quite messy - it forces it to have a site-wide filter for it.

I hope you understand where I'm coming from with this.  
Please feel free to critique and discuss this so we can get a viable working solution that everyone's happy with!

I've also taken the liberty of updating the README.md file in this pull request.

Regards,

Mark.