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
Notes:
* Most tools here have been updated, only a few (unused :p ) features should be missing. But some updates are rough for now, and performances are globally worse currently, will address this later (this is only really noticeable when you work over the whole repo, anyway ;) ).
* This update breaks "edit translations" addon, will fix it later, once core (i.e. this module) is considered stable again!
