Merge remote-tracking branch 'remotes/berrange/tags/pull-io-channel-base-2015-12-18-1' into staging

Merge I/O channels base classes

# gpg: Signature made Fri 18 Dec 2015 12:18:38 GMT using RSA key ID 15104FDF
# gpg: Good signature from "Daniel P. Berrange <dan@berrange.com>"
# gpg:                 aka "Daniel P. Berrange <berrange@redhat.com>"

* remotes/berrange/tags/pull-io-channel-base-2015-12-18-1:
  io: add QIOChannelBuffer class
  io: add QIOChannelCommand class
  io: add QIOChannelWebsock class
  io: add QIOChannelTLS class
  io: add QIOChannelFile class
  io: add QIOChannelSocket class
  io: add QIOTask class for async operations
  io: add helper module for creating watches on FDs
  io: add abstract QIOChannel classes

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