More debug, eliminate some conditions

Do not avoid FIRE, cells get marked like that even
if the bomb has not exploded.

Signed-off-by: Aharon Campos <aharoncampos@gmail.com>
Mark lists and current position as volatile

Because they're being accessed from several threads.

Also, try to ignore bombs which theorethicaly can't hit me.

TODO: need to store the actual firepower of the player who
placed the bomb, to know how much I should care about.

Signed-off-by: Aharon Campos <aharoncampos@gmail.com>