Pyxel

- Fixed the way to quit the Pyxel application
- Fixed Python version check

- Updated the installation instructions of the READMEs
- Added the link to the Discord server to the READMEs
- Added variable frame rate support for animated GIF
- Added the mouse_wheel variable
- Added the fullscreen option to the init API
- Changed the way to quit the Pyxel application
- Removed the border options of the init API
- Changed the required version of Python

- Improved the animated GIF making method
- Added the README in Portuguese
- Fixed to work with Python 3.7 on Windows
- Changed the color change shortcuts to ignore the alt keys

- Fixed the version check of the resource file
- Fixed the typo of the PURPLE variables
- Added the uninitialized error
- Added support for command key shortcuts in Pyxel Editor
- Fixed undo and redo of the sound/music editor
- Changed color comparison method when importing images
- Updated the SDL to 2.0.10
- Updated the SDL_image to 2.0.5
- Changed dll search method for Python 3.8
- Updated the READMEs
- Added KEY_NONE constant to ignore key input
- Added pget API and renamed pix to pset
- Changed the palette colors
- Added new Pyxel palette file
- Changed the animated GIF making method

- Added the tri and trib APIs
- Modified the install option in the READMEs
- Added the quit_key option to the init API
- Added the target options to the load APIs
- Added the partial load function to Pyxel Editor
- Added Example 8
- Modified Example 5

- Added the Korean version of the README