TechRacer: Fix gears not spawning on turn start when player pressed control right at start
The activationStage was horribly programmed and heavily relied on timer. There was a sweet spot
at turn start that if you managed to push a key right at the start of turn, you skip the Ready
phase and the activationStage would advance, causing the gear spawning code to be skipped.
This fix greatly simplies the spawning phase.
07f3bf8d98a3
Hedgewars.png had a resolution more than twice as high as required; also fixed some (mostly obsolete) code that also contained a typo that would cause a warning/note in clang
