Fix the lag produced by oversized Pumpkings (spookofix)

The oversized bounds were interacting with space transitions (removed them, sorry Remie but i didn't felt like doing a hacky check for one seasonal event).

Reduced the number of meteors to 10 waves of 3 over 40 seconds (since Byond seems to be not-so-good at drawing that many large sprites).

_Note :  those event belongs to the halloween sicrit file, don't they ?_