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/obj/251.obj

@@ -39,7 +39,7 @@ A thick green ape cloak is lying here.~
 E
 green thick cloak~
    Green ape cloaks are worn mainly by the chimpanzees.  Due to their thickness,
-they provide decent armour.
+they provide decent armor.
 ~
 A
 18 2
@@ -61,16 +61,16 @@ A
 A
 19 1
 #25104
-black leather gorilla armour armor~
-black gorilla armour~
-Some black leather gorilla armour is lying here.~
+black leather gorilla armor armor~
+black gorilla armor~
+Some black leather gorilla armor is lying here.~
 ~
 9 0 0 0 0 ad 0 0 0 0 0 0 0
 7 0 0 0
 5 600 20 0
 E
-black leather gorilla armour armor~
-   This black leather ape armour is worn only by Gorillas.  It doesn't offer
+black leather gorilla armor armor~
+   This black leather ape armor is worn only by Gorillas.  It doesn't offer
 very good protection, as this suit is worn with a few holes in it.
 ~
 #25105