Release 0.11.0

• SASL EXTERNAL support (XEP-0178)
• Client certificate can be provided for TLS negotiation. If the certificate contains a single xmppAddr and JID is not provided with xmpp_conn_set_jid(), the xmppAddr is chosen as JID
• element contains "from" attribute over TLS connections now
• GnuTLS can be selected optionally with configure script
• Support for manual certificate verification
• New API:
  • xmpp_conn_set_client_cert()
  • xmpp_conn_cert_xmppaddr_num()
  • xmpp_conn_cert_xmppaddr()
  • xmpp_conn_set_cafile()
  • xmpp_conn_set_capath()
  • xmpp_conn_set_certfail_handler()
  • xmpp_conn_get_peer_cert()
  • xmpp_tlscert_get_ctx()
  • xmpp_tlscert_get_conn()
  • xmpp_tlscert_get_pem()
  • xmpp_tlscert_get_dnsname()
  • xmpp_tlscert_get_string()
  • xmpp_tlscert_get_description()
  • xmpp_tlscert_free()