Unify Unification Branches

This affects harakiri, enable_threads and mules.

This does not actually do anything right now, since the combination of
loop_control and (include|import)_*, but in 2.6.y or 2.7 it should work.

For reference: https://github.com/ansible/ansible/issues/42301

Add /tmp exec remount guard around git.
Fix ssh key name