Fix exceptions if project path contains non-utf8 characters (#204)
Fix exceptions if project path contains non-utf8 characters (#204)

Django converts byte strings in various places to unicode by decoding them from
utf-8, which will break if the filesystem encoding uses something else
(e.g. fileystem encoding is latin1 and the path contains german umlauts).

Avoid these problems by explicitly decoding all paths to unicode using an
appropriate encoding.

normanjaeckel/OpenSlides,jwinzer/OpenSlides,FinnStutzenstein/OpenSlides,boehlke/OpenSlides,FinnStutzenstein/OpenSlides,CatoTH/OpenSlides,jwinzer/OpenSlides,emanuelschuetze/OpenSlides,rolandgeider/OpenSlides,CatoTH/OpenSlides,emanuelschuetze/OpenSlides,FinnStutzenstein/OpenSlides,rolandgeider/OpenSlides,OpenSlides/OpenSlides,jwinzer/OpenSlides,ostcar/OpenSlides,rolandgeider/OpenSlides,OpenSlides/OpenSlides,emanuelschuetze/OpenSlides,jwinzer/OpenSlides,normanjaeckel/OpenSlides,FinnStutzenstein/OpenSlides,CatoTH/OpenSlides,tsiegleauq/OpenSlides,normanjaeckel/OpenSlides,tsiegleauq/OpenSlides,boehlke/OpenSlides,emanuelschuetze/OpenSlides,ostcar/OpenSlides,tsiegleauq/OpenSlides,jwinzer/OpenSlides,ostcar/OpenSlides,boehlke/OpenSlides,normanjaeckel/OpenSlides,CatoTH/OpenSlides,boehlke/OpenSlides