`cei:back/cei:note` is not displayed in single charter view

Created by: GVogeler

app/charter/xsl/cei2html.xsl covers only cei:divNotes/cei:note, e.g. in http://monasterium.net/mom/DE-StaAWuerzburg/WuerzburgerRatsurkunden/711/charter see #704 (closed) for additional cei:note-problems