* In a previous update in 2021 many copyright ranges were truncated
accidentally, and some files have been copy-pasted with wrong years. These
dates have been fixed based on git history and original copyright messages.
* We have some special handling to allow SWIG wrapping of these types:
SDFile owns the chunks and buffers within, and each object owns its
children. Copying is disallowed except from SWIG where we assume the
wrapper is handling lifetime management for its objects externally.