plainMessagePart: do not return fileIds if they are not submitted
cleaned up maybeEmptyJson
add signature to message
signature => signatures
changed structure of message signature
make signatures optional
update model, return number of unread messages
added migration, finished call that marks messages as read
return unread messages in all conversation calls
udpated documentation
updated events
added getAccount to authRequest
added account settings
refactored events
refactored tracking of unread messages
finished events, apply settings everywhere
added tests for events
added subvalues to ModelUpdate
updated documentation, fixed tests
udpated documentation