connections now are in: lib/ansible/runner/connection_plugins
callbacks: lib/ansible/callback_plugins
This was done to avoid a conflict between callbacks.py and the package
name on some versions of Python, and I wanted
both to be consistent with each other.
It was either this or break API compatibility by moving the
callbacks.py class, and I did not want to do that.
These directories were never supported for a released version, so it's
the much better option.
--Michael