Life support status timer resets when ship is unfocused

[elldritch]

This might be related to #26.

When I switch away from a ship with USI-LS and then switch back to it, the timer in the life support status indicator is reset, but the actual life support timer itself is not reset. For example:

1. Ship shows 14 days before starving.
2. Fly 7 days to Minmus. The indicator now shows 7 before starving.
3. Switch to another ship, then switch back. The indicator now shows 14 days before starving.

However, this does not reset the actual life support timer -- after 7 more days, the Kerbal will become grouchy despite the indicator showing 7 days remaining. This makes the mod almost unusable.

Not sure if this is related, but all the ships I've flown so far carry no supplies (so their Kerbals are starving).