PositionChanged signal arguments are in the wrong order

[I tried to generate a patch with commit message and such form my local bzr commit but I failed. Thus I'm putting this here. Should be easy enough to pick it up and commit it on your side.]

--- Commit message ---
  Fix the argument ordering of the position signal.

  Signals are supposed to be emitted with the same argument ordering as the reply
  of the method call. Fields comes before the timestamp here. This is the way the
  geoclue dbus spec describes it and the other provider implementing it.

  Be aware that it my break applications that have been developed for the Ubuntu
  provider only and are listening for position signals.

  Signed-off-by: Stefan Schmidt <email address hidden>
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Without this patch the timestamp gets used for the fields and surprising results are the outcome. The attched patch fixes this issue for me.