Release notes

• Allow backslash (\) in filenames on Linux and macOS #3936
• Fixed nested ping-pong tags #4271
• Fixed wrong alignment between mouse and sensor threshold position #4428
• Fixed painting with right-click with custom brush paints with background color #4013
• Lua API:
  • New app.os object
  • Added recent parameter to SaveFile/ExportSpriteSheet commands to avoid adding the file to the list of recent files
  • Disable progress bar in commands that can receive ui=false #4165
  • Fixed bugs handling errors inside app.transaction() #3276 #4431
  • Fixed return values of os.execute()
  • Ask permissions for io.popen()/lines()/input()/output() functions

Full Changelog: https://github.com/aseprite/aseprite/compare/v1.3.6...v1.3.7