Added a "lights out" event.
Flashlights
Red toolboxes now have only a 50% chance to spawn a flashlight (to add diversity and make the lights out event less easy to circumvent).
Explosions
Explosions are now round. This is quite a big balance change, so it's subject to change in the future.
Hydroponics
Hopefully fixed the bug with invading weeds etc being unharvestable.
git-svn-id: http://tgstation13.googlecode.com/svn/trunk@1516 316c924e-a436-60f5-8080-3fe189b3f50e