Improved HTML rendering, command line client and Web service

1. added support for rendering tags with the white-space: pre CSS attribute (e.g. <pre> which is often used for formatting code).
2. API change: A ParserConfig object replaces the parameters display_images, dedpulicate_captions, display_links and indentation in get_text() and for initializing the Inscriptis class.

      from lxml.html import fromstring
      from inscriptis.model.config import ParserConfig
      
      html_tree = fromstring(html)   
      # optional parser configuration fine tuning
      config = ParserConfig(display_links=True, display_anchors=True)
      parser = Inscriptis(html_tree, config)
      text = parser.get_text()

3. command line client:
   • added option for displaying anchor links
   • --encoding not sets the HTML and output encoding
   • new --version option
4. Web service
   • use the related CSS profile per default
   • added version call
5. Documentation fixes and improvements