AGENT-830 cn-agent docker_exec task should support AttachConsole for 'docker attach'
AGENT-830 cn-agent docker_exec task should support AttachConsole for 'docker attach'

joyent/sdc-cn-agent,richardkiene/sdc-cn-agent,joyent/sdc-cn-agent,joyent/sdc-cn-agent,richardkiene/sdc-cn-agent