Update stage_3 to use multi-stack install

Add support for multi-stack installation

Cleanup use of sudo for copying files. Apply docker specific
configuration inside user directory.

Utilize multiple juju controllers utilizing the stack name.

Create stack with no exposed host ports via '-nohostports' for creating
multiple instances of osm (useful in CI)

Add osmclient container for stack: This allows user to run osmclient
inside a container, that matches the release of osm, that has internal
access to all services.

Added options:
    --nolxd for CI osm installation
    --nojuju for CI osm installation
    --nodockerbuild
    --nohostports
    --nohostclient
    -s <stack name>

Change-Id: I4a2c1b09854e61ebb52d83f9f1ecebed8a17674d
Signed-off-by: Mike Marchetti <mmarchetti@sandvine.com>