		Bookmarks - preprocessing
A bookmark-file is taken and the corresponding web-pages are downloaded into the Buffer-directory. 
These pages are freed from HTML-code, in order to extract a plaintext-file with the contents of the page. 
The resulting files are put into the 'Plaintext Directory'.
4 modes are available:
  1 - clear:       clears the Directory and gets all in the bookmark-file referenced pages
  2 - overwrite:   gets the pages overwriting files from a previous run
  3 - add new:     only gets the pages, that haven't been downloaded before
  4 - use present: only uses the HTML-pages from the Buffer-directory. It is the only mode 
                   that doesn't require a Bookmark-File.