Tests needed for config_install:

   cleanup()
      - Fail if cache_dir from previous run cannot be deleted
      - Fail if cache_dir cannot be created from current out_dir

   filter()
      - ensure logformat is changed: target host is prefixed:
         LOGLEVEL: target_host: MESSAGE

   link_emulator():
      - ensure that links to ALL types are created
      - ensure that links points to correct executable
         - i.e. readlink() works
         - AND target of readlink is the correct executable

   remote_mkdir()
      - is directory created

   remove_remote_path
      - is path removed

   transfer_path
      - is src to dst transferred?

emulator:
   may only be called with __ as prefix - fail otherwise!