cli: print errors to stderr in all format modes.
cli: print errors to stderr in all format modes.

This often results in much better end-user-facing behavior if you're, say, piping the output of commands into `jq` -- it's formatted for readability, and it *doesn't block* or have a chance of getting mangled.

Signed-off-by: Eric Myhre <2346ad27d7568ba9896f1b7da6b5991251debdf2@exultant.us>

polydawn/rio,polydawn/rio