Remove 'America' (A) from 'USA' :-)

This to make the country code consistent with mkiocccentry (and I guess
international standard country codes).

This affects many README.md files and (for one line) winners.csv.

1994/README.md

@@ -43,7 +43,7 @@ The ideal 3rd judge would have all of the following:
     * reasonable written communication skills (able to write README.md files)
     * appreciation for well-written non-obfuscated code
     * willing to devote ~4 weekend days in January (starting Jan 96) for judging
-    * located in the San Francisco (California, USA) Bay Area, or
+    * located in the San Francisco (California, US) Bay Area, or
       able to travel (paying your own way) to the SF Bay Area during judging, or
       able to link to the other IOCCC judges some form of a a video link
 

1994/dodsond1/README.md

@@ -4,7 +4,7 @@ Don Dodson
 AG Communication Systems  
 17239 N. 19th Ave. #1003  
 Phoenix, AZ 85023    
-USA  
+US  
 
 ## To build:
 

1994/dodsond2/README.md

@@ -4,7 +4,7 @@ Don Dodson
 AG Communication Systems  
 17239 N. 19th Ave. #1003  
 Phoenix, AZ 85023    
-USA  
+US  
 
 ## To build:
 

1994/horton/README.md

@@ -5,7 +5,7 @@ AT&T Bell Labs
 Rm 1H-117  
 6200 E Broad St.  
 Columbus OH 43213  
-USA  
+US  
 
 ## To build:
 

1994/ldb/README.md

@@ -4,7 +4,7 @@ Laurion Burchall
 Brown University
 Unit 4641
 Providence RI 02912-4641
-USA
+US
 
 ## To build:
 

1994/schnitzi/README.md

@@ -4,7 +4,7 @@ Mark Schnitzius
 ISX Corporation  
 1165 Northchase Pkwy, Suite 120  
 Marietta, GA 30067  
-USA  
+US  
 <http://computronium.org/ioccc.html>  
 
 

1994/shapiro/README.md

@@ -4,7 +4,7 @@ Andrew T. Shapiro
 CSES/CIRES University of Colorado  
 Campus Box 216  
 Boulder, CO 80309-0216  
-USA  
+US  
 
 ## To build:
 

1994/smr/README.md

@@ -4,7 +4,7 @@ Szymon Rusinkiewicz
 Massachusetts Institute of Technology  
 305 Memorial Dr., Room 005B  
 Cambridge, Ma  02139    
-USA  
+US  
 
 ## To build:
 

1994/weisberg/README.md

@@ -5,7 +5,7 @@ University of Rochester
 Dept of Electrical Engineering  
 Computer Studies Bldg  
 Rochester, NY 14627  
-USA  
+US  
 
 ## To build:
 

1994/westley/README.md

@@ -4,7 +4,7 @@ Brian Westley (Merlyn LeRoy on Usenet)
 Digi International  
 1906 James Ave.  
 St. Paul, MN  55105  
-USA  
+US  
 <http://www.westley.org>  
 
 ## To build: