Moderngl

* imgui integration no longer relies on pyopengl
* Bug: Properly parse `out` attributes with layout qualifiers
* Bug: Do not cache system shaders at module level.
We now cache them in the context to better support multiple windows.
* Bug: OrbitCameraWindow - Fixed radians/degree issue
* Bug: A window can now be closed from inside `render()`

* Fixed several issues causing the window close callback not being called
* Fixed incorrect mouse button mapping in mouse drag events

* imgui renderer now supports moderngl textures. This opens up for both
displaying images and animated framebuffer textures into imgui.
* Scene: Fixed several issues related to shader assigning based on material properties.
This especially affected wavefront/obj files.
* OrbitCamera: Fixed translation issue (Leterax)
* OrbitCamera: Now using degrees instead of radians (Leterax)
* Bumped pyglet version to minimum 1.5.6. This version
solves several issue with window events for MacBooks with Touch Bar

* `WindowConfig` now supports overriding the default arugment parser.
A classmethod `add_arguments` can be implemented to add additional
arguments. The parsed arguments are available in `self.argv`
* Added in `Scene.draw_wireframe` rendering a scene in wire frame mode
* `Scene.draw_bbox` now support passing in a `color`
* `Scene` should now have better support for all the vertex formats
wavefront/obj files may have.
* Addded `WindowConfig.clear_color` attribute so uses can control the
clear color of the screen. The value can be set to `None` to
disable screen clearing (Leterax)
* Added `OrbitCamera` (Leterax)
* Allow setting camera rotation (Leterax)
* `VAO` should now give better feedback if the buffers and program
attributes are not compatible
* `ModernGLRenderer` (imgui renderer) should not rely on moderngl-window (minuJeong)
* `Scene` should now cache default shaders internally so they are not loaded
for every scene
* Several typos in docs (dawid-januszkiewicz)
* `WindowConfig.load_compute_shader` missing in docs
* Bumped pygame to `2.0.0.dev10`

Thanks to Leterax, minuJeong and dawid-januszkiewicz for the contributions to this release
and mtbouchard for input on `WindowConfig` and `Scene` changes.

Improvements

* Optimized the imgui renderer using `ctypes` instead of `numpy` for handling vertex data (aforren1)
* Added support for ALT key modifier in all window backends and other improvements to key handling (OKaluza)
* `WindowConfig` now supports a `fullscreen` attribute

Thanks to Alex Forrence (aforren1) and Owen Kaluza (OKaluza) for the contributions to this release.

New Features

* moderngl and moderngl-window integration for imgui thought the pyimgui project.
This is fairly experimental and the rendered should probably be moved to the pyimgui project soon

> Dear ImGui is a bloat-free graphical user interface library for C++. It outputs optimized vertex buffers that you can render anytime in your 3D-pipeline enabled application. It is fast, portable, renderer agnostic and self-contained (no external dependencies)

* Compute shader support. `WindowConfig.load_compute_shader` and added `compute_shader` parameter for `ProgramDescription`.
* Shaders now support `include` up to a maximum of 100 levels
* Added support for gif anim. This can be loaded as a `Texture` or `TextureArray`
* Added support for loading cube maps
* `WindowConfig.run()` shortcut
* Each window backend now has a `name` property so the user can easily detect what window type they are given
* `WindowConfig` now as a `vsync` property so the user can easily control this from python code
* Scene: New methods to find materials and node by name

Slightly Breaking Changes

* All windows now use 0 samples (MSAA) by default. The default `samples = 4` caused way too much issues
for people with older integrated gpus and when doing headless rendering when multisampling is not supported.

Bug fixes

* Fixed several issues with glft2 scenes and object orientation
* pyglet window: Fixed incorrect mouse position on retina screens and windows
with pixel ratio > 1.
* sdl2: mouse press/release events was reversed
* pygame2: Fix broken mouse wheel reading
* glfw: Incorrect mapping of BACKSPACE key
* glfw: Fixed an issue not setting vsync properly¨
* headless: We now call `ctx.finish()` in `swap_buffers`
* Shader errors should now report the error line more accurately
* Various typo fixes