message: update CHANGELOG.md for PR
diff: - Updated misc internal dependencies and dev-dependencies (lazy_static, cgmath, rand, image, gl_generator).
  - Replaced the `IntoVerticesSource` trait with `Into<VerticesSource>`.
  - Fixed [rendering bug](https://github.com/glium/glium/issues/1657) on high-DPI screens.
  + - Added support for clipping via `gl_ClipDistance`.
  ## Version 0.19.0 (2017-12-11)
  