• RetroCoreView: Add the key press, key release and touch event masks
  to ensure it receives all the events it can handle, and hence to
  ensure that these input methods work as expected.
  
• Meson: Add the vapi option to allow disabling building Vala bindings.
  
• Documentation:
  
  • Add the Libretro Core Descriptor Specification 1.0 section.
    
  • Add the Retro Reference Test Case Specification 1.0 section.
    
• Clean up the documentation, README.md, HACKING.md, retro-gtk.doap,
  .editorconfig, update-from-retroarch, the Meson files, and more.