This commit mainly finishes up refactor by fixing everything brought up in the CR + Improving NCE somewhat and actually killing the child processes properly now.
We earlier moved to LGPLv3.0 or Later. This was a mistake as what we wanted was being able to link to proprietary libraries but LGPL is the opposite and it allows linking proprietary libraries to libskyline instead. After further consideration, we've moved to MPL-2.0, it allows linking to proprietary libraries and is a standardized license as compared to adding an exception to GPL.
This makes some tiny changes to audio to make them compliant with the guidelines. In addition, to changing `IUserManager:IUserManager` to `sm:IUserManager`.