- ``global-writable-files``: A list of global writable file infos. The list
  elements must have the following format::

    global_writable_file_info	::= path [ "directory" ] [ "keep-old" | "manual" | "auto-merge" ]

  ``path`` is the relative path of the writable file or directory, starting with
  "settings/" or any other writable directory. If the "directory" keyword is
  given, the path refers to a directory. If no other keyword is given after the
  path respectively after the "directory" keyword, the file or directory is not
  included in the package. It will be created by the software or by the user.
  If a keyword is given, the file or directory (a default version) is included
  in the package and it will be extracted on package activation. The keyword
  specifies what shall happen when the package is updated and a previous default
  version of the file or directory has been modified by the user:

  - "keep-old": Indicates that the software can read old files and the
    user-modified file or directory should be kept.
  - "manual": Indicates that the software may not be able to read an older file
    and the user may have to manually adjust it.
  - "auto-merge": Indicates that the file format is simple text and a three-way
    merge shall be attempted (not applicable for directories).