v2.14

[Ko van der Sloot]

• implemented an ADD_FORMATTING TextPolicy to extract otherwise hidden
  text from <t-hspace> and <t-hyph> Markup elements
  (see proycon/foliapy#25)
• fix for #51
• General improvements:
  • include a filename when throwing during Document processing
  • added setutest() member for XmlText class
  • general code quality