Merge remote-tracking branch 'remotes/kraxel/tags/ui-20181001-pull-request' into...

ui: some small fixes/improvements.

# gpg: Signature made Mon 01 Oct 2018 11:42:16 BST
# gpg:                using RSA key 4CB6D8EED3E87138
# 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>"
# Primary key fingerprint: A032 8CFF B93A 17A7 9901  FE7D 4CB6 D8EE D3E8 7138

* remotes/kraxel/tags/ui-20181001-pull-request:
  gtk: add zoom-to-fit to gtk options.
  vnc: call sasl_server_init() only when required
  sdl2: show console #0 unconditionally

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