* Add very basic "Add to homescreen" action in manga info fragment.
* Fix open from homescreen opening current manga (if a manga is open).
Code cleanup.
* Improve fix for "Opening from homescreen opens currently open manga if a manga is currently open" and fix "Going back to the main app via a Manga opened through a shortcut repeats the launcher open animation".
* Implement custom icons, add star icon and optimize some things.
* Remove Tachiyomi and custom image icon types.
* Move icon creation task into an observable.
Added some extra error handling.
