Move licenses to LICENSES/, use SPDX-License-Identifier, mention all licenses in galaxy.yml (ansible-collections#430)

* Move licenses to LICENSES/, use SPDX-License-Identifier, mention all licenses in galaxy.yml.

* ignore.txt lines cannot be empty or contain only a comment.

* Cleanup.

* This particular __init__.py seems to be crucial.

* Try extra newline.

* Markdown comments are a real mess. I hope this won't break Galaxy...

* More licenses.

* Add sanity test.

* Skip some files, lint.

* Make sure there is a copyright line everywhere.

* Also check for copyright line in sanity tests.

* Remove colon after 'Copyright'.

* Normalize lint script.

* Avoid colon after 'Copyright' in lint script.

* Improve license checker.

* Update README.md

Co-authored-by: Maxwell G <9920591+gotmax23@users.noreply.github.com>

* Remove superfluous space.

* Referencing target instead of symlink

Co-authored-by: Maxwell G <9920591+gotmax23@users.noreply.github.com>

Author: felixfontein

.azure-pipelines/README.md

@@ -1,3 +1,8 @@
+---
+# 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
+
 trigger:
   batch: true
   branches: