i think it only makes sense to have an "opinion" for command line
interface in this project, and we probably need more `wutta`
subcommands too but we'll see.
main motivation for this currently is to allow poser apps to define
their own CLI, in particular e.g. `poser install`
this has 100% test coverage and i intend to keep it that way. api
docs have a good start but still need narrative. several more things
must be added before i can seriously consider incorporating into
rattail but this seemed a good save point