Add CocoaPush support to CocoaPods.org

-- DO NOT MERGE --

This pull request is for discussion and implementation of a user interface for CocoaPush.

As I know nothing about design or frontend JS, I would appreciate input as to how it might work.

My current thinking is that the results, when hovered over, could have a button slide out that says "notify me". This will then add the pod to the user's list of desired pods, and, if necessary, initiate the request for permissions etc.

Through a runtime check for safari push notification permissions we can display a link at the top of the page, or on the page, to a small panel allowing the user to manage their settings: namely, to remove registered pods. Deregistration from push notifications should be done through Safari preferences. 

This user settings page is keyed, unfortunately, on a per computer basis. Without a user account framework we are unable to share notifications or their settings between computers, but I believe the simplicity of no login is worth the tradeoff, both in technical debt and user experience.

cc @orta, as design dictator, and anyone else who knows JS.