Fix spelling in MissionPackageGUI

Signed-off-by: Chris Forbes <chrisf@ijw.co.nz>
Fix spurious apostrophes in FinanceWindowGUI

Signed-off-by: Chris Forbes <chrisf@ijw.co.nz>
Fix spelling of Manager.TotalSpentVehicles

Signed-off-by: Chris Forbes <chrisf@ijw.co.nz>
Merge pull request #19 from chrisforbes/fixes

spelling Fixes