Implement expires_in() for Alarm.
Implement expires_in() for Alarm.

Useful to find out how much time is left on an alarm.

dansut/Cosa,jeditekunum/Cosa,rrobinet/Cosa,dansut/Cosa,kc9jud/Cosa,kc9jud/Cosa,jeditekunum/Cosa,rrobinet/Cosa,kc9jud/Cosa,mikaelpatel/Cosa,mikaelpatel/Cosa,mikaelpatel/Cosa,mikaelpatel/Cosa,jeditekunum/Cosa,dansut/Cosa,kc9jud/Cosa,dansut/Cosa,jeditekunum/Cosa,rrobinet/Cosa,rrobinet/Cosa