Merge remote-tracking branch 'remotes/kraxel/tags/pull-ui-20160118-1' into staging

ui: misc small gtk/spice/vnc patches.

# gpg: Signature made Mon 18 Jan 2016 15:52:13 GMT using RSA key ID D3E87138
# gpg: Good signature from "Gerd Hoffmann (work) <kraxel@redhat.com>"
# gpg:                 aka "Gerd Hoffmann <gerd@kraxel.org>"
# gpg:                 aka "Gerd Hoffmann (private) <kraxel@gmail.com>"

* remotes/kraxel/tags/pull-ui-20160118-1:
  vnc: fix tls-creds error message
  Fix corner-case when using VNC+SASL+SPICE
  vnc: clear vs->tlscreds after unparenting it
  gtk: implement set_echo

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>