Add remaining copyright statements, add licenses sanity test (#5098)

* Add sanity test (currently fails).

* doc_fragments can also be non-GPLv3+.

* Replace 'Author:' by 'Copyright:' in some specific cases.

* Avoid matching string for license checkers.

* Reformulate not to throw license detection off.

* Add PSF copyright notice for plugins/module_utils/_mount.py.

* Add generic copyright notices.

* Update changelog fragment.

tests/integration/targets/jboss/tasks/jboss.yml

@@ -4,8 +4,8 @@
 # Integration tests for jboss module.
 # SPDX-License-Identifier: GPL-3.0-or-later
 
-# helloworld.war (got from https://github.com/aeimer/java-example-helloworld-war/) license:
-# MIT License
+# helloworld.war (got from https://github.com/aeimer/java-example-helloworld-war/) is licensed
+# under the MIT license:
 #
 # Copyright (c) 2017 Alex Eimer
 #

tests/integration/targets/kernel_blacklist/tasks/main.yml

@@ -49,7 +49,7 @@
     expected_content: |
       # Copyright (c) Ansible Project
       # GNU General Public License v3.0+ (see LICENSES/GPL-3.0-or-later.txt or https://www.gnu.org/licenses/gpl-3.0.txt)
-      # SPDX-License-Identifier: GPL-3.0-or-later
+      # SPDX-{{ '' }}License-Identifier: GPL-3.0-or-later
 
       blacklist aaaa
       blacklist bbbb
@@ -76,7 +76,7 @@
     content: |
       # Copyright (c) Ansible Project
       # GNU General Public License v3.0+ (see LICENSES/GPL-3.0-or-later.txt or https://www.gnu.org/licenses/gpl-3.0.txt)
-      # SPDX-License-Identifier: GPL-3.0-or-later
+      # SPDX-{{ '' }}License-Identifier: GPL-3.0-or-later
 
       blacklist aaaa
       blacklist bbbb
@@ -104,7 +104,7 @@
     content: |
       # Copyright (c) Ansible Project
       # GNU General Public License v3.0+ (see LICENSES/GPL-3.0-or-later.txt or https://www.gnu.org/licenses/gpl-3.0.txt)
-      # SPDX-License-Identifier: GPL-3.0-or-later
+      # SPDX-{{ '' }}License-Identifier: GPL-3.0-or-later
 
       blacklist aaaa
       blacklist cccc