accelerate is stuck down if a game is saved with that key pressed

[Riot]

i.e. entering a tunnel

[Riot]

reset stateful player ship controls when claiming them, resolves #222 and any other stuck-key-on-load issues

→ <<cset d79fbc4b760c>>

[Riot]

reset rotation and acceleration when player ship claims its controls, re #215 and #222

→ <<cset f6731000cef1>>

[Riot]

Removing milestone: Beta (automated comment)