* Manage creation/loading/removal/migration of accounts via AccountController
* Instantiate AccountMigrationController on demand
* GlobalDrawer: List accounts and show button to add new accounts
* Show dialog to select account for global action such as adding a contact
* Depend several controllers/managers on each account instead of having singletons
* Manage account settings, connection state, caches, account-related controllers via Account
* Run all account-related controllers on main thread
* Run only ClientWorker and DiscoveryManager on XMPP thread
* Add getters for QXmpp managers to ClientWorker and use them by controllers
* Rename Kaidan to MainController
* Make Database/Settings singletons
* Instantiate ChatController via ChatPage
* Instantiate MessageModel/ChatHintModel via ChatController avoiding singletons
* Move parts related to current chat from GroupChatController to ChatController
* Allow to enable/disable accounts instead of connecting/disconnecting manually
* Hide actions in details if account is disabled
* Remove methods for temporarily connecting to execute tasks
* Log QXmpp's debug messages
* Fix OMEMO initialization
* Do not try to automatically add unknown JIDs multiple times
* Split up RosterFilterProxyModel into RosterFilterModel and GroupChatInviteeFilterModel
* Request own vCard once connected to get current nickname
* Show small account avatars next to regular avatars if multiple accounts are used
* Hide global drawer handle on ChatPage if window is narrow
* Use less bold font for headings
* Hide expansion button for media overview if no media available
* Rename UserListItem to AvatarItemDelegate and RosterListItem to RosterItemDelegate
* Create common ContactDelegate for various delegates that contain avatar and heading

This needs QXmpp 1.11.0