updates to comet scene

debris spawn rate depends on distance to comet, it now cuts off at 900m as they look shit closeup
made the debris spawn rate adjustable
sped up the bits of debris to increase levels of impending doom

collision alerts for debris about to hit ship. Turned off flickery damage effect when cable puzzle is running because its really fucking annoying

added random hull pinging sounds when in the comet scene
comet scene stuff

changed drop scene and comet scene to broadcast distance to death using the /ship/state/altitude message instead of their own custom ones

added new sounds for comet scene, one for general bg noise and one whilst approaching death
added support for dropping comet fragments into the ships path