Roll back ad04d21fda

As was discussed with Landon this was a mistake even if it helped with
consistency. There was even a brilliant pun that was destroyed with that
commit which I think is worth pointing out:

    cp README.md hill
    ./ant hill

in 1991/ant ... even if it's technically 'anthill'.

I hope that I got all links fixed in years.html and winners.html. As
well I tried to make sure I got all handles fixed in all/summary.txt.
Nevertheless these should be checked. For some handles they were never
updated (at least in the html files - though maybe summary.txt too, not
sure) in the first place so there was nothing to do.

Typo fixes like references to *.hint when it should be README.md. There
probably are others that need to be fixed but haven't been located yet.

1990/theorem/README.md

@@ -0,0 +1,116 @@
+# Best of Show
+
+	Adrian Mariano
+	University of Washington
+	2729 72nd Ave SE
+	Mercer Island, WA 98040
+	USA
+
+
+## To build:
+
+        make all
+
+NOTE: thanks to Yusuke Endoh for the pointing out that `atof()` nowadays needs
+`#include <stdlib.h>` in order to get this to work. Thanks also to Cody Boone
+Ferguson for fixing some segfaults under modern (and in some cases earlier)
+systems with this entry.
+
+
+## To run:
+
+	./mariano expression x1 x2 h y1
+
+where:
+
+	expression - function f(x,y)  (see below)
+	x1 - start of interval
+	x2 - end of interval
+	h - step size
+	y1 - initial value  (y(x1) == y1)
+
+
+## Try:
+
+	./mariano y 0 1 0.1 1
+
+
+
+## Judges' comments:
+
+The program's source implements four functions, all from the
+same source file!
+
+When you compile mariano.c as is and run with 5 args, it numerically
+solves the equation y'=f(x,y), with a step size of h, over the interval 
+x=[x1,x2], with the initial condition of y(x1)=y1.
+
+The 'expression' f(x,y), is any function of 'x' and 'y' with the
+operators:
+
+	    +	-	*	/	^
+
+The symbol '^' is the power operator.  Note that it only supports
+integer powers.  Also note that all expressions are evaluated strictly 
+left to right.  (i.e., parenthesis aren't supported).
+
+Try running the program with the following args:
+
+	./mariano y 0 1 0.1 1
+	./mariano 1/x 1 2 0.1 0
+	./mariano 'x^2/y+x' 0 1 0.1 6
+
+But wait, there is more!  You also get, free of charge, a 
+reversing filter!  Try:
+
+	./mariano -r 0 0 0 0 < mariano.c > sorter.c
+
+Still not impressed?  The author throws in for free, a 
+sort program! Try:
+
+	cc sorter.c -o sorter
+	ls | ./sorter
+
+This program is safe for home use as well.  The author has
+included a safety feature in case you misplace the original
+program source:
+
+    ./sorter -r 0 0 0 0 < sorter.c > mariano_bkp.c
+
+And finally, as a special offer to users of this entry,
+the author provides a Fibonacci sequence generator!  Try:
+
+    ./sorter 0 0 0 0 < mariano.c > fibonacci.c
+    cc fibonacci.c -o fibonacci
+    ./fibonacci 1 1
+    ./fibonacci 2 1
+
+Program available 9 track and cartridge cassette.  Gensu knife
+not included!  :-)
+
+When this program was first shown at the 1990 Summer Usenix 
+conference, it received a standing ovation; a first for
+a contest entry.
+
+Originally we noted that the 4 trailing args '0 0 0 0' were required on systems
+that dump core when NULL is dereferenced but this problem showed itself in
+modern systems even with the 4 '0 0 0 0'. To make this easier for users Cody
+Boone Ferguson kindly fixed this problem.
+
+
+## Author's comments
+
+Differential equations are solved via the Runge-Kutta method, 
+which guarantees local error proportional to h^5, and total
+error across a finite interval is at most a constant times h^4.
+
+Sorting is accomplished with a standard shell sort.
+
+Note that the sorting and reversing is limited to files with 
+fewer than 500 lines, each less than 99 characters long.  
+
+Copyright (c) 1990, Landon Curt Noll & Larry Bassel.
+All Rights Reserved.  Permission for personal, educational or non-profit use is
+granted provided this this copyright and notice are included in its entirety
+and remains unaltered.  All other uses must receive prior permission in writing
+from both Landon Curt Noll and Larry Bassel.