Tcod

Added
- `BasicMixer` and `Channel` classes added to `tcod.sdl.audio`. These handle simple audio mixing.
- `AudioDevice.convert` added to handle simple conversions to the active devices format.
- `tcod.sdl.audio.convert_audio` added to handle any other conversions needed.

Added
- `tcod.sdl.audio`, a new module exposing SDL audio devices. This does not include an audio mixer yet.
- `tcod.sdl.mouse`, for SDL mouse and cursor handing.
- `Context.sdl_atlas`, which provides the relevant `SDLTilesetAtlas` when one is being used by the context.
- Several missing features were added to `tcod.sdl.render`.
- `Window.mouse_rect` added to SDL windows to set the mouse confinement area.
Changed
- `Texture.access` and `Texture.blend_mode` properties now return enum instances.
You can still set `blend_mode` with `int` but Mypy will complain.

Added
- Adds `sdl_window` and `sdl_renderer` to tcod contexts.
- Adds `tcod.event.add_watch` and `tcod.event.remove_watch` to handle SDL events via callback.
- Adds the `tcod.sdl.video` module to handle SDL windows.
- Adds the `tcod.sdl.render` module to handle SDL renderers.
- Adds the `tcod.render` module which gives more control over the rendering of consoles and tilesets.
Fixed
- Fixed handling of non-Path PathLike parameters and filepath encodings.

Added
- New experimental renderer `tcod.context.RENDERER_XTERM`.
Changed
- Using `libtcod 1.20.1`.
Fixed
- Functions accepting `Path`-like parameters now accept the more correct `os.PathLike` type.
- BDF files with blank lines no longer fail to load with an "Unknown keyword" error.

Added
- New `console` parameter in `tcod.context.new` which sets parameters from an existing Console.

Changed
- Using `libtcod 1.20.0`.

Fixed
- Fixed segfault when an OpenGL2 context fails to load.
- Gaussian number generation no longer affects the results of unrelated RNG's.
- Gaussian number generation is now reentrant and thread-safe.
- Fixed potential crash in PNG image loading.

Added
- Added the `tcod.tileset.procedural_block_elements` function.
Removed
- Python 3.6 is no longer supported.