Settings with time units

[mitfik]

Instead of raw numbers:

maximum_unused_login_ticket_lifetime: 300
maximum_unused_service_ticket_lifetime: 300
maximum_session_lifetime: 172800

3d => 3 days
5h => 5 hours
1s => 1 second

etc...

[tpickett66]

good idea, I've pulled ActiveSupport for use in my fork and it shouldn't be too tough to implement the parsing of this format.