Fix countdown logic of re-sortie.

fixed #9
Merge branch 'improve-resortie-countdown'

Conflicts:
	Grabacr07.KanColleViewer/ViewModels/Fleets/FleetViewModel.cs
	Grabacr07.KanColleViewer/Views/Fleets.xaml
	Grabacr07.KanColleWrapper/Repairyard.cs