Always force current_author_id to UPPERCASE.
Inflate package_version into a version object.
Simplify response processing callback.

We know that all data chunks will be individual lines,
so we don't have to line-buffer them on the client.

This also fixes the problem of not showing blank lines
properly (visible in the "log" command output).
Add constant for the progress message.
The is_interactive test isn't really what we want.

What matters is whether STDERR is a tty or not.  That's all.