Document exhaustive licensing info of all files
Document exhaustive licensing info of all files

Uses the machine-readable debian/copyright standard to be explicit
about both the licenses and the corresponding copyright attributions
for Godot source files and thirdparty libraries bundled in the source
repository.

(cherry picked from commit e776a1ebb288042f6a835443c57842f42df563ab)

pixelpicosean/my-godot-2.1,pixelpicosean/my-godot-2.1,pixelpicosean/my-godot-2.1,pixelpicosean/my-godot-2.1,pixelpicosean/my-godot-2.1