Add COPYING files.

In order to help static analysis tools such as GitHub's Licensee license
detector, this change makes the overall project license easier to see by
copying LICENSES/LGPL-3.0-or-later.txt to COPYING and removing all other
COPYING.* files.

Change-Id: I7658a33c256e127930f9d6303d827ffdb42a4a62
2 files changed