Instead of having an annoying loop that constantly reschedules a
Core::EventLoop trigger, have the ALooperEventLoopManager do it itself
in the did_post_event() function.
We cannot simply re-use the Unix implementation directly because that
implementation expects to actually be called all the time in order to
service timers. If you don't call its' pump() method, timers do not get
triggered. So, we do still need the seconary thread for Timers that was
added earlier.