example: bring examples in from the examples repository.
example: remove LICENSE, README.md, doc.go
README: mention example directory.
example: don't include TMX examples right now.
mv example/assets/textures -> example/textures
example: rename azul3d_foobar -> gfx_foobar
example: fix absolute path resolution
Merge pull request #45 from azul3d/v2-example

v2: add graphics examples