+) lib/clock_alphabet::CLOCK_TICK --- "'"
+) lib/clock_event::clock_event_toStr()
+) lib/clock_event::clock_event_findClosestFromList()
+) lib/clock_main::checkButton() macro
+) lib/clock_main::clock_state_showEvents()
+) test/ut_clock_event::clock_state_showEventstest_clock_event_findClosestFromList_correct()

*) lib/clock_main::slideText() now accepts an optional callback which should be
   called when the slideText() completes. If it is not NULL, _nextState_ and
   _nextStepMillis_ will be ignored and the callback will be called.