- Always use templatetag 'absolute_url' instead of (depricated) 'model_url'.
Search and replace all old arguments: edit -> update, view -> detail, delete
- Fixed bug in setting default value in 'absolute_url' templatetag
(default value is defined in models.py only).
Updated 'backend' template.
* Set a static projector title
* absolute_urls for the activate links
* update the projector when a slide changes (in save())
* insert the absolute_url template filter
* Preview to slides
* renamed is_active to is_active_slide
* The SlideMixin has to come before the PersonMixin
* Update list of speakers
* Render Countdown via JS
* Reconnect projector after connection lost
* Overlays can allways be active and do not appear in the widget
* Rewrote the clock as overlay
