adding support for ownCloud 5.0.9
removing unnecessary code and debugging information
refactored owncloud repo setup and added pinning (security)
re-introduced autoconfig

rational:
    - owncloud doesn't use the values set in config.php when prompting the
      user to finalize the setup. it automatically defaults to an sqlite
      configuration.
    - even if it did work, it opens a race-condition security hole
    - having the appliance automatically configured out of the box allows
      the use of inithooks and preseeding
minor refactor of code snippets ordering
regenerate passwordsalt on firstboot (security)