Replaced the original MIT license with a new BSD-style license.

Chris Hanson from MIT Scheme granted the new license in a private
email on 12 Dec 2003.

scheme/srfi/srfi-13.scm

@@ -2053,36 +2053,36 @@
 ;;; details.
 ;;;     -Olin Shivers
 
-;;; MIT Scheme copyright terms
-;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
-;;; This material was developed by the Scheme project at the Massachusetts
-;;; Institute of Technology, Department of Electrical Engineering and
-;;; Computer Science.  Permission to copy and modify this software, to
-;;; redistribute either the original software or a modified version, and
-;;; to use this software for any purpose is granted, subject to the
-;;; following restrictions and understandings.
+;;; The MIT Scheme project gave Olin Shivers the permission to use the
+;;; code from this SRFI under the following license:
+;;;
+;;; Redistribution and use in source and binary forms, with or without
+;;; modification, are permitted provided that the following conditions are
+;;; met:
 ;;; 
-;;; 1. Any copy made of this software must include this copyright notice
-;;; in full.
+;;;    1. Redistributions of source code must retain the above copyright
+;;;       notice, this list of conditions and the following disclaimer.
 ;;; 
-;;; 2. Users of this software agree to make their best efforts (a) to
-;;; return to the MIT Scheme project any improvements or extensions that
-;;; they make, so that these may be included in future releases; and (b)
-;;; to inform MIT of noteworthy uses of this software.
+;;;    2. Redistributions in binary form must reproduce the above
+;;;       copyright notice, this list of conditions and the following
+;;;       disclaimer in the documentation and/or other materials provided
+;;;       with the distribution.
 ;;; 
-;;; 3. All materials developed as a consequence of the use of this
-;;; software shall duly acknowledge such use, in accordance with the usual
-;;; standards of acknowledging credit in academic research.
+;;;    3. The name of the author may not be used to endorse or promote
+;;;       products derived from this software without specific prior
+;;;       written permission.
 ;;; 
-;;; 4. MIT has made no warrantee or representation that the operation of
-;;; this software will be error-free, and MIT is under no obligation to
-;;; provide any services, by way of maintenance, update, or otherwise.
-;;; 
-;;; 5. In conjunction with products arising from the use of this material,
-;;; there shall be no use of the name of the Massachusetts Institute of
-;;; Technology nor of any adaptation thereof in any advertising,
-;;; promotional, or sales literature without prior written consent from
-;;; MIT in each case.
+;;; THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+;;; IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+;;; WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+;;; DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
+;;; INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+;;; (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+;;; SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+;;; HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+;;; STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+;;; IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+;;; POSSIBILITY OF SUCH DAMAGE.
 
 ;;; Scsh copyright terms
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;