rough sketch of named envs
rough sketch of named envs

In a separate command for now.  Should merge "use" and "named" into just
"use", and have it be smart enough to know that anything not matching a
release version, "latest" or "stable" is a named env.

isaacs/nave,isaacs/nave,TayNelson/nave,rbaindourov/nave,0xDB/nave,sapics/nave