Fix HISTORY and add AUTHORS section

Obtained from:	OpenBSD (by schwarze@)

usr.bin/mkstr/mkstr.1

@@ -28,7 +28,7 @@
 .\"     @(#)mkstr.1	8.1 (Berkeley) 6/6/93
 .\" $FreeBSD$
 .\"
-.Dd November 1, 2002
+.Dd June 6, 2015
 .Dt MKSTR 1
 .Os
 .Sh NAME
@@ -118,10 +118,16 @@ error(a1, a2, a3, a4)
 .Xr xstr 1 ,
 .Xr lseek 2
 .Sh HISTORY
-An
+The
 .Nm
-utility appeared in
-.Bx 3.0 .
+utility first appeared in
+.Bx 1 .
+.Sh AUTHORS
+.An -nosplit
+.An Bill Joy
+and
+.An Chuck Haley ,
+1977.
 .Sh BUGS
 The
 .Nm