Normally pseudo is built with --without-passwd-fallback, which requires
that somebody provide target passwd and group files. Those come from
base-passwd in OE, but base-passwd cannot be built without first
invoking operations under pseudo that require getpw*/getgr*.
Provide the absolute minimum stub files, matching in content what will
eventually be on the target, that can be used in the cases where the
target files are not yet available. The requirements for minimum stub
are the usernames and groups identified in meta/files/fs-perms.txt.
