Clamped ColorIntensity

Otherwise the color values wrap around and make the circles keep
blinking for a while if the ColorIntensity was set really high, eg. in a
really overpowered explosion.
Reset test explosion force
Renamed weapon:update() to firing(), added update()

Update is always called every frame, even when not firing. This allowed
projectile weapon shot delay to be implemented properly.
Merge remote-tracking branch 'upstream/master'

update
Andrew fixed things