Release 0.13.0

0.13.0
- Fix connected/connecting signaling to user (#227)
- Fix wording of licensing terms (#225)
- Prepare for future changes in OpenSSL (#226)
- Improve Stream Management (#227) (#230)
- Add SCRAM-PLUS Variants (#228)
- Introduce XEP-0138 stream compression (#231)
- Deprecated the following API (#227):
- xmpp_conn_disable_tls() - replaced by a flag set by xmpp_conn_set_flags()