Do not claim other than method call messages as handled

Other message filters will not see the signals unless
DBUS_HANDLER_RESULT_NOT_YET_HANDLED is returned.
Add relative timestamps when logging to stderr

Makes it easier to see time difference between messages when running
mce in debug modes.
Use single state machine for both display and suspend policy

As fb suspend and wakeup are not immediate, display state requests
must be handled separately from actual state transition processing.

A new data pipe display_state_req_pipe is used for making display
state requests and filtering them.

The state machine takes data from display_state_req_pipe and
makes changes known to existing triggers via display_state_pipe.

The suspend policy is integrated to display state handling, which
allows better control over sharing update enable/disable state
with ui side (lipstick).

[mce] Use single state machine for both display and suspend policy
Merge pull request #65 from spiiroin/display_stm

Use single state machine for both display and suspend policy