Adds a sound source as alias for an existing sound source, but with a different name or optional different default settings. This is useful if you want to play multiple sounds but each sound isn't necessarily one single file. Also useful if you want to or play the same sound using different names, volumes or min and max 3D distances.
Returns the pointer to the added sound source or 0 if not sucessful because for example a sound already existed with that name. If not successful, the reason will be printed into the log.