Fix division by 0 in sniper rifle training

Sniper rifle training: Fix missing victory sound, also disable controls at the end String freeze notice: This commit will display a caption with the string "Victory!". It does NOT violate the string freeze, as this string is already present in stub.lua.

Sniper rifle mission: Faster dynamite blow-up, also skip with precise

Sniper rifle training: Fix general camera weirdness - Camera bounced back and forth between shots - FollowGear was called every 20ms (way too often) - Now camera only re-centers when using sniper rifle - Camera also centers to dynamite once

Sniper rifle mission: Fix targets spawning twice in dynamite scenes, jacking up the total amount of targets

Fix small German typo

Fix GCC warnings: -Wimplicit-fallthrough and -Wint-in-bool-context