Add support for active alarm windows in MPAS timekeeping

This commit introduces active alarm windows, allowing alarms to be
constrained by explicit start and stop times. New helper functions
mpas_add_clock_alarm subroutine now accepts optional alarmStartTime and
alarmEndTime arguments, which default to the clock's start and end
times.

Author: Andy Stokely

src/core_test/mpas_test_core.F

@@ -242,6 +242,18 @@ function test_core_run(domain) result(iErr)!{{{
       end if
       call mpas_log_write('')
 
+      !
+      ! Test functionality of alarms with user-defined active windows
+      !
+      call mpas_log_write('')
+      call mpas_log_write('Testing mpas_window_alarms:')
+      iErr = mpas_window_alarm_tests(domain)
+      if (iErr == 0) then
+         call mpas_log_write('* mpas_window_alarm tests - all tests passed: SUCCESS')
+      else
+         call mpas_log_write('* mpas_window_alarm tests - $i failed tests: FAILURE', intArgs=[iErr])
+      end if
+
       deallocate(threadErrs)
 
    end function test_core_run!}}}