Modifed execute cli to run docker images.

Review: https://reviews.apache.org/r/24808
require some c++11 features for libprocess

Review: https://reviews.apache.org/r/25168
require some c++11 features for mesos

Review: https://reviews.apache.org/r/25169
Fail when no command provided with shell enabled in docker.

Review: https://reviews.apache.org/r/24987
Merge branch 'master' into disk_isolation_containerization