Fixed a lot of text, mostly in simple_animal.  The word "the" was being ...

...duplicated in a lot of cases when referring to objects or mobs.  Basically, byond handles "the" for us.  Poly was particularly guilty of this, but really it was all simple_mobs.

Also fixed issue 566, where it was possible to weaken corpses.  Dead humans, humanoid aliens, and larvae should no longer be weakenable once they're dead.

Also also, changed the default name for human mobs from unknown to Unknown.  This is makes them consistent with humans whose identities are destroyed by acid or face damage.  They'll no longer show up as "The unknown" in messages, since Byond recognizes Unknown as a proper noun due to capitalization.  Still awkward, but more consistent.

Finally, gave Runtime a DNA joke as a description.  Not sure why she didn't have a description.