all: update for new MIT license

On March 23, 2021, Nokia transferred the copyrights in the Plan 9 software
to the Plan 9 Foundation, which relicensed them under the MIT license.

This commit updates the Plan 9 from User Space license to reflect the
new base license. The vast majority of the contributions beyond the
base Plan 9 set were by me, many of them explicitly under an MIT license.
Those are all under the new MIT license now as well.

The port of mk to Unix was taken from Inferno via Vita Nuova and had
been made available under GPL, but Vita Nuova has relicensed Inferno
under the MIT license as well, to match the new Plan 9 license.

Michael Teichgraber contributed src/lib9/zoneinfo.c explicitly under
the Lucent Public License but has agreed to change the contribution
to the MIT license now used in the rest of the distribution.

There remain a few exceptions, most notably fonts.
See the root LICENSE file for full details.

The only mention of the Lucent Public License in the whole tree now
is in the LICENSE file, explaining the history.

4 files changed, 4 insertions, 41 deletions

diff --git a/src/lib9/LICENSE b/src/lib9/LICENSE
index 12e3eba5..c6665b2b 100644
--- a/src/lib9/LICENSE
+++ b/src/lib9/LICENSE
@@ -1,8 +1,7 @@
-The files listed below may be redistributed either under the
-terms of the Lucent Public License version 1.02 or under the
-terms of the simpler MIT-style license at the bottom of this file.
 The files listed below were written from scrach for plan9port
 and do not derive from the Plan 9 from Bell Labs distribution.
+They are made available under an MIT-style license, using the
+same terms as the main distribution.
 
 	../../include/u.h
 	non-Plan 9 code in ../../include/libc.h
@@ -70,11 +69,7 @@ and do not derive from the Plan 9 from Bell Labs distribution.
 	time.c
 	truerand.c
 	udp.c
-	unsharp.c	
-
-The other source files in this directory do derive from Plan 9 and
-are distributed only under the terms of the  Lucent Public License
-version 1.02, as detailed in ../../LICENSE.
+	unsharp.c
 
 Copyright 2001-2007 Russ Cox.  All Rights Reserved.
 
diff --git a/src/lib9/fmt/NOTICE b/src/lib9/fmt/NOTICE
deleted file mode 100644
index 5dc21cb5..00000000
--- a/src/lib9/fmt/NOTICE
+++ /dev/null
@@ -1,19 +0,0 @@
-/*
- * The authors of this software are Rob Pike and Ken Thompson.
- *		Copyright (c) 2002 by Lucent Technologies.
- * Permission to use, copy, modify, and distribute this software for any
- * purpose without fee is hereby granted, provided that this entire notice
- * is included in all copies of any software which is or includes a copy
- * or modification of this software and in all copies of the supporting
- * documentation for such software.
- * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR IMPLIED
- * WARRANTY.  IN PARTICULAR, NEITHER THE AUTHORS NOR LUCENT TECHNOLOGIES MAKE ANY
- * REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE MERCHANTABILITY
- * OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR PURPOSE.
-*/
-
-This is a Unix port of the Plan 9 formatted I/O package.
-
-Please send comments about the packaging
-to Russ Cox <rsc@post.harvard.edu>.
-
diff --git a/src/lib9/utf/NOTICE b/src/lib9/utf/NOTICE
deleted file mode 100644
index ad76cd52..00000000
--- a/src/lib9/utf/NOTICE
+++ /dev/null
@@ -1,13 +0,0 @@
-/*
- * The authors of this software are Rob Pike and Ken Thompson.
- *              Copyright (c) 1998-2002 by Lucent Technologies.
- * Permission to use, copy, modify, and distribute this software for any
- * purpose without fee is hereby granted, provided that this entire notice
- * is included in all copies of any software which is or includes a copy
- * or modification of this software and in all copies of the supporting
- * documentation for such software.
- * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR IMPLIED
- * WARRANTY.  IN PARTICULAR, NEITHER THE AUTHORS NOR LUCENT TECHNOLOGIES MAKE ANY
- * REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE MERCHANTABILITY
- * OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR PURPOSE.
- */
diff --git a/src/lib9/zoneinfo.c b/src/lib9/zoneinfo.c
index f8ae442d..36b4b6ef 100644
--- a/src/lib9/zoneinfo.c
+++ b/src/lib9/zoneinfo.c
@@ -6,7 +6,7 @@
  * Formats 0 and 2 are supported, and 4-byte timestamps
  *
  * Copyright © 2008 M. Teichgräber
- * Contributed under the terms of the Lucent Public License 1.02.
+ * Contributed under the MIT license used in the rest of the distribution.
  */
 #include "zoneinfo.h"