libcontainer v0.0.4 introduces setting `/proc/self/oom_score_adj` to better tune oom killing preferences for container process. This patch simply integrates OomScoreAdj libcontainer's config option and adjust the cli with this new option. Signed-off-by: Antonio Murdaca <amurdaca@redhat.com> Signed-off-by: Antonio Murdaca <runcom@redhat.com>