`rp` is obscure enough to go ahead & spam the terminal with help upon very likely unintended weak params.  Also convert tty stdin to /dev/null or its Windows analogue.  Also re-arrange/document imports a bit.
`rp` is obscure enough to go ahead & spam the terminal with help upon
very likely unintended weak params.  Also convert tty stdin to /dev/null
or its Windows analogue.  Also re-arrange/document imports a bit.

c-blake/cligen