Merge remote-tracking branch 'remotes/armbru/tags/pull-error-2015-11-03' into staging

vl.c: Error message rework

# gpg: Signature made Tue 03 Nov 2015 08:40:50 GMT using RSA key ID EB918653
# gpg: Good signature from "Markus Armbruster <armbru@redhat.com>"
# gpg:                 aka "Markus Armbruster <armbru@pond.sub.org>"

* remotes/armbru/tags/pull-error-2015-11-03:
  vl.c: Use "%s support is disabled" error messages consistently
  vl.c: Improve warnings on use of deprecated options
  vl.c: Touch up error messages
  vl.c: Remove unnecessary uppercase in error messages
  vl.c: Use "warning:" prefix consistently on warnings
  vl.c: Remove periods and exclamation points from error messages
  vl.c: Replace fprintf(stderr) with error_report()

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