Optionally print message and clock_gettime when started

[samueldr]

To track where time is spent during a boot, this should optionally print to the logs time information.

I'm thinking about the equivalent to Process.clock_gettime(Process::CLOCK_MONOTONIC).

The idea being that we can guesstimate how much time was spent between bootlogd and the real init.

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By default we might want to print something like:

printf("bootlogd vXXX starting at ~%.6d...\n, time)"

This would additionally give a clue as to what prints this.

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Make this a compile-time option, as /init can't be given params really.