Contentline.__str__: Fix utf-8 line-folding problem.
Contentline.__str__: Fix utf-8 line-folding problem.

From http://codespeak.net/pipermail/icalendar-dev/2010-April/000152.html

Signed-off-by: Rok Garbas <91d1dd8615d34a96099572be3f37ee9127974eeb@garbas.si>

nylas/icalendar,geier/icalendar,untitaker/icalendar