Add a recipe specifically for Google Analytics

Assigning to myself, because this is essentially renaming the drupal_cms_analytics recipe and establishing a new subtree split for it. We still have the drupal_cms_analytics recipe and we can keep it where it is, but it will just not be updated until we actually have a recipe for it.

This makes sense to me, I agree with the approach.

Okay - I've created the drupal_cms_google_analytics namespace.

Merged into 1.x. This will hopefully free up some flexibility to use different analytics services in different ways, while still presenting a relatively unified set of tools.