Update Arsenal.py

Added spacing to the OnUnloadGamePlay argument.
Merge pull request #1 from sipster19/patch-1

Update Arsenal.py
Added useful information to OnPlayedKilled()'s description

I've mentioned that players can be killed by map "hurt" triggers and by changing their team.

I've also mentioned how the "weapon" and "killer" parameters can be used to find out when a player has been killed by one of these causes.