D3 used to support Aureal 3-Dimensional sound cards, providing 3D spatial audio. The hardware and drivers is outdated, so all support in code has been removed, including UI mixer setting.
Read more about A3D here: https://en.wikipedia.org/wiki/Aureal_Semiconductor#A3D
This definition was used to control the accessibility of some class members, changing protected qualifiers to public. This introduced unnecessary coupling between components and headers.
All conditional access specifiers have been set to public, which should not be a problem given the low number of classes that actually used affected members. Another albeit more complex solution could have been to use friend classes.
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.
