Keep checking if we are whitelisted and request it if not

Also fixed an issue with notifications alerting again when items
were removed.

This prevents a crash on Android 4 when the package name in build.gradle differs from the name in the manifest.

Also close keyboard when returning from message fragment

All text that can be generated by users will show emoji from the
shipped sprites.

For all messages and posts, the custom emoji keyboard is now available.

This also disables menu actions rather than hiding them and thus
closes #677

Included is a fix for a regression that was not showing the keyboard
automatically in forums and thus
closes #676

Add functionality to save and restore recently used Emojis

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

Closes #342

This refactors the forum invitation code,
so it can be used by both: forums and blogs.

This commit refactors the code for sharing forums,
so it can be used for sharing blogs as well.

It does not yet include code for responding to blog invitations.

Closes #517