feature, debug: make simulator write a logbook entry When compiling the code with -DSIM_WRITES_LOGBOOK, the simulator writes to the logbook. This is for debug purpose only. This commit does *not* define this SIM_WRITES_LOGBOOK, so when compiled, things are functionally unchanged. Caveat 1: a simulator generated log cannot be advanced with +5 min. It needs to run in real time. Caveat 2: The generated log is currently not "complete". For example, CCR setpoint switches are not logged. There are likely more small events not logged. This means that a sim generated log is not a full replacement for real dive testing. Signed-off-by: Jan Mulder <jlmulder@xs4all.nl>