imagefactory: Print working directory for logs

So I can find them...
Clean up ImageFactory code, move IF-specific bits from TaskBase

The ImageFactory code had some leftover generic bits from when this
code was one big script.  Kill those.
imagefactory: We actually export raw images

Until this gets fixed...
lorax-embed-repo: Remove remote configuration for install media

It's not useful, because it points at the local content.