Rename sniper_status column to sniper_state
Rename sniper_status_changed to sniper_state_changed
Collapse sniper_state into SniperSnapshot
Use sniper_state_changed to notify that the sniper is winning
Add state change methods to SniperSnapshot
Remove redundant sniper_winning method
Add SniperState class, and collapse state change methods
Fix features to check for correct values (all passing again!)