File headers: SPDX License migration

Use a shorter/simpler license convention, stops the header taking so
much space.

Follow the SPDX license specification: https://spdx.org/licenses

- C/C++/objc/objc++
- Python
- Shell Scripts
- CMake, GNUmakefile

While most of the source tree has been included

- `./extern/` was left out.
- `./intern/cycles` & `./intern/atomic` are also excluded because they
  use different header conventions.

doc/license/SPDX-license-identifiers.txt has been added to list SPDX all
used identifiers.

See P2788 for the script that automated these edits.

Reviewed By: brecht, mont29, sergey

Ref D14069

1 files changed, 2 insertions, 15 deletions

diff --git a/intern/sky/source/sky_nishita.cpp b/intern/sky/source/sky_nishita.cpp
index 236c965fb27..f1eab181189 100644
--- a/intern/sky/source/sky_nishita.cpp
+++ b/intern/sky/source/sky_nishita.cpp
@@ -1,18 +1,5 @@
-/*
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- *
- * Copyright 2011-2020 Blender Foundation
- */
+/* SPDX-License-Identifier: Apache-2.0
+ * Copyright 2011-2020 Blender Foundation. */
 
 /** \file
  * \ingroup intern_sky_modal