- Better control of when to create/remove vardir


mysql-test/mysql-test-run.pl:
  Split the part the function cleanup_stale_files in two parts
    - one that removes any old var directories
    - one that setup var in te proper location
  
  If running against extern server and no vardir has been created in the specified
  location, run the latter function to create the vardir structure. Else print
  message saying the vardir already exists and continue.