Add kCFStreamSSLPeerName when starting TLS
Add kCFStreamSSLPeerName when starting TLS

This accomplishes two things:
1. We verify the hostname when connecting via TLS. This ensures that DNS spoofing will not work.
2. MQTT will now use SNI which allows proxies like HAProxy to forward based on the host name.
zl00/CocoaMQTT,zl00/CocoaMQTT