Standardize on American spellings.

Full internationalization would be much cooler, but that's never going
to happen.  Given that, this will at least prevent folks from constantly
having to look and switch between typing "armor" and "armour", depending
on which zone each item originated in, etc.

I could flip these either way, but a survey of the current state shows
that about 80% of the mixed cases use the American spellings, while 20%
use the British.  And, most words *only* exist in this data in their
American forms.  So, it seems the majority prefer these spellings.

In case anyone likes trivia:
* The most common mixed words in here were "armour" and "colour", each of
  which occured about half as often as "armor" and "color", respectively.
* The most British word in here was "theatre" (including other forms),
  which occured about twice as often as "theater".

This stanardizes all of these (and other forms of these same words):
* armour -> armor
* colour -> color
* favour -> favor
* honour -> honor
* civilise -> civilize
* centre -> center
* theatre -> theater
* defence -> defense
* offence -> offense
* realise -> realize

lib/world/mob/150.mob

@@ -166,7 +166,7 @@ Peter, the Captain of the Royal Guard~
 Peter, the Captain of the Royal Guard, walks around inspecting.
 ~
    As all members of the Guard, Peter wears the chain mail required of them as
-uniform.  Even though all the other guards seem well trained, you realise none
+uniform.  Even though all the other guards seem well trained, you realize none
 of them would stand a chance against this man in a fight.  He stands at least
 two metres tall, but still moves with an almost feline grace.  He actually
 radiates strength and confidence, and you have to fight a sudden urge to come to