Allow setting of AWS creds and region on the command line.
Rename "projinfo.js" to "loadTemplate.js".

That's the only thing it actually does these days.
Resolve some uses of {Ref} and {Fn::FindInMap} inside Boxen decls.

This is required if you want to e.g. use a different base AMI depending
on the target region.  It's nice to use the same syntax as CloudFormation
runtime.