Arbitrarily coloured blood and footprints.

Optimizes footprint tracks using code stolen wholesale from /vg/station, with many thanks to N3X15 and other coders. 

Also implements species-derived blood colour from human mobs and arbitrarily coloured blood splatters.

Gibs are TBD.

See also: LGBT pride parade massacre. http://i.imgur.com/G4YhEAc.png