FIXUP ContactUser use Connection purpose
WIP Add ChatChannel
FIXUP Rename data classes for ChatChannel
Add missing license headers to ConversationModel
Use a context when connecting lambdas to a signal

The connection is removed when the context object is deleted, which
will make sure the lambda's captured pointers remain valid.
FIXUP AHSC inverted if
Add Connection::channelOpened signal
PROTOCOL_NEW Add ContactUser::connection
PROTOCOL_NEW Port ConversationModel to new protocol
WIP Add Channel::openChannel method
FIXUP Connection::channelOpened signal when the channel is actually open
Add message queuing in ConversationModel
WIP Add ContactRequestChannel
WIP Disable old protocol code in OutgoingContactRequest
WIP Connection behavior for OutgoingContactRequest
FIXUP OutgoingContactRequest add basic channel logic
FIXUP ContactRequestChannel impl
FIXUP ContactRequestChannel.proto
FIXUP ContactRequestChannel add setMessage and setNickname methods
FIXUP ContactRequestChannel nickname optional