Merge remote-tracking branch 'remotes/stefanha/tags/tracing-pull-request' into staging

# gpg: Signature made Thu 07 Jan 2016 09:13:22 GMT using RSA key ID 81AB73C8
# gpg: Good signature from "Stefan Hajnoczi <[email protected]>"
# gpg:                 aka "Stefan Hajnoczi <[email protected]>"

* remotes/stefanha/tags/tracing-pull-request:
  trace: add make dependencies on tracetool source
  trace: fix make foo-timestamp rules
  trace: fix PRIx64 constants in trace-events
  trace: reflect the file name change

Signed-off-by: Peter Maydell <[email protected]>