reset TUs on stage 2 of missions

and reduce copypasta
fix melee

getCurrentAction() only works for player actions.
initialize that variable at once!
Fix crash on victory/defeat screens.
Fix scrollbar drawing incorrectly at small sizes.
Fixes to autosaves.
Fixed more autosave weirdness.
Fixed scientists/engineers vanishing when mod was missing.
Fixed dogfight buttons sticking.
Fixed plurality in extra strings