hints and SSH keys

pycreateuser doesn't currently support ssh public keys or password hints. We do this out of band, but it seems more appropriate to do it in pycreateuser. Let me know if you think it is worthwhile and I'll do a pull request.

[gregneagle]

Since password hints are stored in the dslocal user record, I'd say that's "in scope", but ssh keys are files in the home directory, so I'd say that's out of scope for the tool.

[gregneagle]

I think the most common use of pycreateuserpkg is to create a pkg that installs a local admin user or other local "utility" user and so password hints have never really been a common need.