License: address review feedback on the rc2 fixes

Follow-up to the review of the previous commit:

- README.apache.md: list the Greenplum-era companies as copyright
  holders, not as contributors under the Apache License 2.0.  Metapa
  had become part of Greenplum long before Greenplum Database was
  released under the Apache License 2.0 in 2015.  Put the list in date
  order.
- LICENSE, Greenplum section: call the Metapa notice a legacy notice
  instead of an "older" one: its 2005 date is not older than the
  Greenplum notices around it.  Leave the merger year out.
  Move the Apache License statement to the start of the section and
  point it to the top of this file rather than to "(see LICENSE)".
  With that statement first, the sentence saying the files are covered
  by the same license is no longer needed, so drop it, along with a
  stray second "All Rights Reserved." line.
- LICENSE, BSD section: src/include/getopt_long.h and
  src/include/pg_getopt.h carry only a "Portions Copyright ... The
  Regents of the University of California" line, with no BSD license
  text.  List them on their own as headers derived from BSD getopt.
- LICENSE, build system section: list the top-level configure script,
  which carries the FSF's unlimited-permission notice, under the FSF
  All-Permissive License, and retitle the section to match.
- pom.xml: config/ax_pthread.m4 is GPL-3.0-or-later with the Autoconf
  Macro exception, but its RAT exclude sat under a GPLv2 comment.  Give
  it a comment of its own.  Word the Metapa comment in the Greenplum
  license family the same way as LICENSE.

Assisted-by: Claude Code

Author: tuhaihe

LICENSE

@@ -244,9 +244,7 @@ The PostgreSQL software includes:
       Code from the BSD C library, each file under its own University of
       California copyright notice and the 3-clause BSD terms (in some
       files the rescinded advertising clause is left as a numbered gap):
-      src/include/getopt_long.h
       src/include/lib/sort_template.h
-      src/include/pg_getopt.h
       src/port/bsearch_arg.c
       src/port/fls.c
       src/port/getopt.c
@@ -255,6 +253,13 @@ The PostgreSQL software includes:
       src/port/pgmkdirp.c
       see licenses/LICENSE-bsd3-regents.txt
 
+      Headers derived from BSD getopt, which carry only a "Portions
+      Copyright (c) 1987, 1993, 1994 The Regents of the University of
+      California" line:
+      src/include/getopt_long.h
+      src/include/pg_getopt.h
+      see licenses/LICENSE-bsd3-regents.txt
+
       MD5 and SHA-1 implementations from the KAME project:
       src/common/md5.c
       src/common/md5_int.h
@@ -481,26 +486,22 @@ Greenplum Database
 
 Copyright (c) 2004-2020 VMware, Inc. or its affiliates. All Rights Reserved.
 
-All Rights Reserved.
+Greenplum Database is licensed under the Apache License Version 2.0 (see
+the top of this file) and is based on the PostgreSQL Database Management
+System.
 
 Files that came from Greenplum Database carry the copyright notice of
 whoever owned the code when they were written: Greenplum, Inc., EMC
 Corporation, Pivotal Software, VMware, Inc., or, for some ORCA query
 optimizer files added in 2024, "Copyright (C) 2024 Broadcom" or
 "Copyright (C) 2024 VMware by Broadcom".  Three management scripts carry
-an older "Copyright (c) Metapa 2005" notice; Metapa merged with Didera in
-2003 to form Greenplum:
+a legacy "Copyright (c) Metapa 2005" notice; Metapa was one of the two
+companies that merged to form Greenplum:
 
    gpMgmt/bin/gpinitsystem
    gpMgmt/bin/lib/gp_bash_functions.sh
    gpMgmt/bin/lib/gpcreateseg.sh
 
-All of these files are part of Greenplum Database and are covered by the
-same license.
-
-Greenplum Database is licensed under the Apache License Version 2.0
-(see LICENSE) and is based on the PostgreSQL Database Management System.
-
 The Greenplum Database software includes:
 
 ----------------------------
@@ -714,15 +715,17 @@ Apache Cloudberry includes codes from
        contrib/pax_storage/src/cpp/contrib/tabulate/utils/amalgamate/LICENSE.md)
 
 ================================================================================
-Build system files under config/
+Build system files
 
-These files come from the GNU Autotools (Autoconf, Automake and
-Libtool), pkg-config and the Autoconf Archive.  The GPL-licensed ones
-carry an exception for use in configure scripts generated by Autoconf,
-which is the basis on which the ASF allows such build-tool files in its
-distributions (https://www.apache.org/legal/resolved.html#build-tools;
-see also LEGAL-290).  Each file carries its full license notice, and the
-generated configure script includes expansions of these macros.
+The files under config/ come from the GNU Autotools (Autoconf, Automake
+and Libtool), pkg-config and the Autoconf Archive.  The GPL-licensed
+ones carry an exception for use in configure scripts generated by
+Autoconf, which is the basis on which the ASF allows such build-tool
+files in its distributions
+(https://www.apache.org/legal/resolved.html#build-tools; see also
+LEGAL-290).  Each file carries its full license notice.  The top-level
+configure script is generated by Autoconf, includes expansions of these
+macros, and carries its own notice; it is listed below.
 
 ----------------------------
    GNU General Public License, with an exception for use in configure
@@ -757,6 +760,9 @@ generated configure script includes expansions of these macros.
 ----------------------------
    FSF All-Permissive License
 
+      configure, generated by GNU Autoconf 2.69
+         Copyright (C) 1992-1996, 1998-2012 Free Software Foundation, Inc.
+
       Macros from the Autoconf Archive:
 
       config/ax_compare_version.m4

README.apache.md

@@ -27,18 +27,18 @@ This file documents licensing clarifications and exceptions as part of ASF relea
 
 This file is licensed under the GPL (Category X) and has been removed from the source tree to comply with ASF release policy.
 
-## Historical Attribution Under Apache License 2.0
+## Historical Copyright Notices in Greenplum-based Code
 
-The following entities have contributed to the Greenplum-based source code under the Apache License 2.0:
+Files that came from Greenplum Database carry the copyright notices of the companies that owned the code when it was written:
 
-- Metapa (merged with Didera in 2003 to form Greenplum)
+- Metapa (one of the two companies that merged to form Greenplum)
 - Greenplum, Inc.
 - EMC Corporation
-- VMware, Inc.
 - Pivotal Software
+- VMware, Inc.
 - Broadcom Inc.
 
-RAT matchers are used to classify their license headers accordingly.
+Greenplum Database was released under the Apache License 2.0 in 2015, and these files are distributed under that license. RAT matchers are used to classify their license headers accordingly.
 
 ## Compressed Files in Source
 

pom.xml

@@ -330,9 +330,11 @@ code or new licensing patterns.
             <exclude>config/python.m4</exclude>
             <exclude>config/tcl.m4</exclude>
 
-            <!-- GPLv2-AUTOEXC -->
+            <!-- GPLv2-or-later with the Autoconf exception -->
             <exclude>config/pkg.m4</exclude>
             <exclude>config/libtool.m4</exclude>
+
+            <!-- GPLv3-or-later with the Autoconf Macro exception -->
             <exclude>config/ax_pthread.m4</exclude>
 
             <exclude>.abi-check/**</exclude>
@@ -2120,7 +2122,7 @@ code or new licensing patterns.
                 <pattern>Copyright (c) 2007 Greenplum Inc</pattern>
                 <pattern>Copyright (c) 2010, Greenplum Software</pattern>
                 <pattern>Copyright (c) Greenplum Inc 2010</pattern>
-                <!-- Metapa merged with Didera in 2003 to form Greenplum. -->
+                <!-- Metapa was one of the two companies that merged to form Greenplum. -->
                 <pattern>Copyright (c) Metapa 2005. All Rights Reserved.</pattern>
                 <pattern>Copyright Greenplum 2008</pattern>
               </patterns>