lib: rename `info` subcommand to `status`
lib: get configuration from `$KETREW_CONFIGURATION`
lib: add `Configuration.log`
lib: add the `print-configuration` subcommand
lib: add debug-level and log-color to `Configuration.t`
lib: add the `interact` sub-command

This also adds the `Interaction` submodule and uses it in `archive` and
`kill`.