* Add default license header to files which have no copyright or license header yet.
* yml extension should have been xml...
(cherry picked from commit 1ab2a5f1bc)
* Do not remove non-ASCII Unicode from multi-line string output.
* Added basic tests.
* Add Unicode test.
* Simplify tests, avoid later Jinja features.
* Refactor.
* Make use diy tests use callback test framework as well.
* Remove color codes.
* Work around stable-2.9 bug.
* Simplify again.