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/shp/120.shp

@@ -15,7 +15,7 @@ CircleMUD v3.0 Shop File~
 -1
 %s We are out of that item right now.~
 %s You don't have that.  Stop wasting my time!~
-%s This is a weapon and armour shop!  Go someplace else!~
+%s This is a weapon and armor shop!  Go someplace else!~
 %s A fine weapon indeed, but more than I can afford.~
 %s NO CREDIT!~
 %s Here you go.  That will be %d coins.  Don't get hurt!~

lib/world/shp/248.shp

@@ -50,10 +50,10 @@ CircleMUD v3.0 Shop File~
 0
 0
 -1
-%s Sorry, I don't have that armour.~
+%s Sorry, I don't have that armor.~
 %s Sorry, you don't seem to have that.~
 %s I don't buy such a item, try some other shop.~
-%s Sorry, that's a too expensive armour for me, try in Thewston.~
+%s Sorry, that's a too expensive armor for me, try in Thewston.~
 %s Get some money if you like to buy something...~
 %s Ok, that'll be %d coins, please.~
 %s Here you are, I'll give you %d coins for it.~

lib/world/shp/54.shp

@@ -186,7 +186,7 @@ CircleMUD v3.0 Shop File~
 -1
 %s Haven't got that on storage - try list!~
 %s You don't seem to have that.~
-%s I only buy armours.. Go away!~
+%s I only buy armors.. Go away!~
 %s That is too expensive for me - Try a wizard!~
 %s You can't afford it!~
 %s That'll be %d coins, please.~