Adding start support to stopped containers when use_name is defined.

This is to solve the issue raised in https://github.com/garethr/garethr-docker/issues/160

use_name was causing issues under RedHat as it would attempt to start a new container with the same name rather than start the existing container.  We now check for the existence of this container before starting.

Note: Interactive and attach were removed from the RedHat version as the current init script forces detached mode anyway.  Detach (or attachment support in general) needs a slight overhaul and will likely be handled in a future PR.