Audit output for STDERR|STDOUT correctness and investigate JSON output

[asgrim]

It probably makes sense to comb through all the existing output, and ensure it is going to the appropriate output pipe (STDERR or STDOUT); for example the version banner probably makes more sense to go to STDERR.

Also at the same time, investigate if it makes sense to add a JSON formatted output for some commands (e.g. pie show).

[krakjoe]

Just to note, most nix tools will print their version info to stdout but provide a --quiet flag for suppression, automatically enabling --quiet for things like json output.

The reason is that a perfectly reasonable thing to do is execute $(tool --version) in shell and expect not to have to redirect stderr.