Convert license statements to SPDX headers

Authored by cordlandwehr on Feb 2 2020, 4:42 PM.

Description

Convert license statements to SPDX headers

Summary:
Convert license statements to SPDX markers and add license files
compatible with REUSE.software specification.

Reviewers: cgiboudeaux

Reviewed By: cgiboudeaux

Subscribers: cgiboudeaux, kde-frameworks-devel

Tags: Frameworks

Maniphest Tasks: T11550

Differential Revision: https://phabricator.kde.org/D27104