- Added message queue : when using "SendX" methods on a client, messages are also stored in a queue. When requesting
acks from the server, sent messages will be discarded, and unsent ones will be sent again. (see https://xmpp.org/extensions/xep-0198.html#acking)
- Added support for stanza_errors (see https://xmpp.org/rfcs/rfc3920.html#def C.2. Stream error namespace and https://xmpp.org/rfcs/rfc6120.html#schemas-streamerror)
- Client state update is now thread safe
- Changed the Config struct to use pointer semantics
- Tests
- Refactoring, including removing some Fprintf statements in favor of Marshal + Write and using structs from the library