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/53.obj

@@ -369,15 +369,15 @@ A
 24 -2
 #5325
 ring sandy~
-a sandy-coloured ring~
-A small sandy-coloured ring has been carelessly dropped here.~
+a sandy-colored ring~
+A small sandy-colored ring has been carelessly dropped here.~
 ~
 9 bg 0 0 0 ab 0 0 0 0 0 0 0
 8 0 0 0
 5 200 75 0
 E
 ring sandy~
-   The ring is small, smooth, sandy-coloured and unremarkable, save that it
+   The ring is small, smooth, sandy-colored and unremarkable, save that it
 gives off a continuous low humming noise that tickles your fingertips.
 ~
 A