Convert to using sdeventplus

This gets rid of the ad-hoc timer class in favor of using the timer
source built into sdeventplus.

Tested:
    Unit tests pass and everything still builds. Manually verified the
    functionality is still in tact on a zaius machine.

Change-Id: I90619f0fe5a9fdfcecd24a49de672c0c99dc95e9
Signed-off-by: William A. Kennington III <wak@google.com>
12 files changed