Fixes and improvements, add stackuser capability

 * Fixes on HOST_IP
 * Fixes on ssh key location
 * Fixes on nova key name
 * Detect if we are running on vagrant or not.. looking to go to
   continuous integrations on the future with other environments.
 * Add the hability to use a differnt user to build devstack
 * Fixes on local.sh
 * Enable dstat service