Merge remote-tracking branch 'remotes/kraxel/tags/pull-audio-20150615-1' into staging

audio: remove obsolete backends (esd, fmod, winwave).
audio: stop using global variables, small fixes.
audio: remove some obsolte and unused code.

# gpg: Signature made Mon Jun 15 13:24:44 2015 BST 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-audio-20150615-1:
  ossaudio: use trace events instead of debug config flag
  alsaaudio: use trace events instead of verbose
  dsoundaudio: remove primary buffer
  dsoundaudio: remove *_retries kludges
  audio: remove plive
  audio: remove LOG_TO_MONITOR along with default_mon
  MAINTAINERS: remove malc from audio
  sdlaudio: do not allow multiple instances
  coreaudio: do not use global variables where possible
  dsoundaudio: do not use global variables
  paaudio: fix possible resource leak
  wavaudio: do not use global variables
  ossaudio: do not use global variables
  alsaaudio: do not use global variables
  paaudio: do not use global variables
  audio: expose drv_opaque to init_out and init_in
  only enable dsound in case the header file is present
  audio: remove winwave audio driver
  audio: remove fmod backend
  audio: remove esd backend

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