Main Layout refers to an outdated jquery CDN resource

The default Main Layout partial in the developer portal CMS refers to an outdated jquery resource from an external CDN.

The CMS already has a more up to date jquery in javascripts and the Main Layout template should just point to that.

This line:

{{ '//ajax.googleapis.com/ajax/libs/jquery/1.7.1/jquery.min.js' | javascript_include_tag }}

Should become:

{{ '/javascripts/jquery.js' | javascript_include_tag }}

This will help to avoid confusion when trying to change the version of jquery.