Clarify libctb getopt license, copyright and provenance

This is the original getopt() implementation by Henry Spencer placed in
the public domain as mentioned in https://irreal.org/blog/?p=6240,
http://esr.ibiblio.org/?p=7552, and where this code can also be found in
https://sources.debian.org/src/apg/2.2.3.dfsg.1-5/getopt.c/?hl=84#L84
for reference including its provenance.

LICENSE

@@ -191,10 +191,12 @@ Copyright: 2001-2010 Joachim Buermann
 License: wxWindows
 
 Files: src/mod/endpoints/mod_gsmopen/libctb-0.16/src/win32/getopt.cpp
-Copyright: 2001 ?
+Copyright: 1984 Henry Spencer
-License: clueless and unacceptable
+License: public-domain
- FIXME -- this cannot go in Debian -- the license is stated as:
+Comment:
-  (I think Open Source)
+ https://irreal.org/blog/?p=6240
+ http://esr.ibiblio.org/?p=7552
+ https://sources.debian.org/src/apg/2.2.3.dfsg.1-5/getopt.c/?hl=84#L84
 
 Files: src/mod/endpoints/mod_rtmp/libamf/src/types.[ch]
 Copyright: 2007, 2008 Marc Noirot <marc.noirot AT gmail.com>

debian/copyright

@@ -191,10 +191,12 @@ Copyright: 2001-2010 Joachim Buermann
 License: wxWindows
 
 Files: src/mod/endpoints/mod_gsmopen/libctb-0.16/src/win32/getopt.cpp
-Copyright: 2001 ?
+Copyright: 1984 Henry Spencer
-License: clueless and unacceptable
+License: public-domain
- FIXME -- this cannot go in Debian -- the license is stated as:
+Comment:
-  (I think Open Source)
+ https://irreal.org/blog/?p=6240
+ http://esr.ibiblio.org/?p=7552
+ https://sources.debian.org/src/apg/2.2.3.dfsg.1-5/getopt.c/?hl=84#L84
 
 Files: src/mod/endpoints/mod_rtmp/libamf/src/types.[ch]
 Copyright: 2007, 2008 Marc Noirot <marc.noirot AT gmail.com>

src/mod/endpoints/mod_gsmopen/libctb-0.16/src/win32/getopt.cpp

@@ -1,10 +1,10 @@
 /////////////////////////////////////////////////////////////////////////////
 // Name:        win32/getopt.cpp
 // Purpose:
-// Author:      unknown, I found it in the internet
+// Author:      Henry Spencer
 // Id:          $Id: getopt.cpp,v 1.1.1.1 2004/11/24 10:30:11 jb Exp $
-// Copyright:   (c) 2001 ?
+// Copyright:   (c) 1984 Henry Spencer
-// Licence:     (I think Open Source)
+// Licence:     public domain
 /////////////////////////////////////////////////////////////////////////////
 
 #include <stdio.h>