Refactor all Push tutorials to single document with TOC pattern

The idea is having the same as we did with UPS guide - one long document where people can navigate using TOC:

http://staging-aerogearsite.rhcloud.com/docs/unifiedpush/ups_userguide/index/

The advantage is that people doesn't have to change the page while still having enough contextual information to handle the structure of long document.

These are the guides I have on mind:

http://staging-aerogearsite.rhcloud.com/getstarted/guides/#push

Tutorial: Android Push Notifications
Tutorial: iOS Push Notifications
Tutorial: JavaScript Push Notifications
Tutorial: Windows Push Notifications
Tutorial: Chrome Packaged Apps Push Notifications