Removes key_emulation and joy_emulation toggles from ddio_init_info structures, that were not used in the SDL implementation.
All input is now handled using SDL for all platforms, alternatejoy/directinput options were only relevant for Windows-specific DirectInput. 'slowkey' was an unimplemented feature.
Join the license header with historical comments using a separator so IDEs can correctly parse the initial header.
Also use .gitattributes to ensure all files are LF.
