Only chown on atomic move if invoked as root

Linux and BSD derivatives do not allow unprivileged users to
"give away" files to others for security reasons. (System V
derivatives allow that but they're rare nowadays.)
Try optimistic chown, do not error out if not permitted to chown

Add unit test
Merge branch 'devel' of https://github.com/l1k/ansible into l1k-devel

Conflicts:
	test/integration/roles/test_copy/tasks/main.yml
Remove tabs added from 677de07
Merge branch 'l1k-devel' into devel