Parametrized, cleaned

 * Parametrize with examples.
 * All synced_folders are included.
 * Print docker version 
 * Add a d alias to docker 
 * Cleanup
 * Vagrantfile of passenger is nearly identical to that of baseimage now.  (I got to that when wanting to try passenger.  But already had a vagrant box started from baseimage, there was no need to dup the effort, just reuse the existing single box for all.  Then in end of day, may not need multiple Vagrantfiles.  Passenger is a simple structure/process for managing dockers, but only needing to use baseimage once and have one VM up.)