to work-around android bug #224270.
This is only necessary if the transitioning view might not be available
anymore when the exit transition is made.

This commit also moves various blog classes into their own packages and
makes the required visibility changes.

Add functionality to save and restore recently used Emojis

Update emoji and add new categories based on AOSP's XML file

by making it only selectable in detail view

This also adds comments to the blog post detail screen that were
previously missing.