The evdev_trace optionally emits local time of day

Command line options can be used to choose
* local time of day + event time stamp
* only local time of day
when emitting event traces.

Note: that time of day = event read time, not the time when the event
was created.

[evdev_trace] The evdev_trace optionally emits local time of day
Merge pull request #97 from spiiroin/evdev_timestamps

The evdev_trace optionally emits local time of day