Add --security-opts options to allow user to customize security configuration

security-opts will allow you to customise the security subsystem.

For example the labeling system like SELinux will run on a container.

    --security-opt="label:user:USER"   : Set the label user for the container
    --security-opt="label:role:ROLE"   : Set the label role for the container
    --security-opt="label:type:TYPE"   : Set the label type for the container
    --security-opt="label:level:LEVEL" : Set the label level for the container
    --security-opt="label:disabled"    : Turn off label confinement for the container

Since we are passing a list of string options instead of a space separated
string of options, I will change function calls to use InitLabels instead of
GenLabels.  Genlabels interface is Depracated.

Docker-DCO-1.1-Signed-off-by: Dan Walsh <dwalsh@redhat.com> (github: rhatdan)