Initial commit of diff tests

Signed-off-by: James Molet <jmolet@redhat.com>
fixed underlines in docs

Signed-off-by: James Molet <jmolet@redhat.com>
Merge branch 'diff' of https://github.com/Lorquas/autotest-docker into docker_0.6.3
subtests...diff: Minor cleanups

Signed-off-by: Chris Evich <cevich@redhat.com>