Animated custom emoji, rich replies, rich text

* Animated custom emoji
* Rich replies, including small image preview and jump-to-parent
* Hide reply quote if it's just the exact previous message
* Allow storing all media in cache on a per-chat basis
* Optional rich text mode
* Option to auto-download any size on unmetered networks
* Use custom tabs for opening links
* Theme tweaks
* Remember avatar and nickname in channels even when user not connected
* Don't treat as a stranger anyone in system contacts
* Ignore archived messages from blocked users
* Menu to delete files from media browser
* Bold timestamp on attention messages
* Start a message with @mods to ping active moderators in a channel
* Fix for dissapearing action buttons in commands
* Fix crash when trying to restore a chat for a nonexistent account
* Fix password change
* Fix unbanning users in channel