Added Portuguese translation (Thanks to Marco A.G.Pinto)
Merge pull request #890 from emanuelschuetze/translation-pt

Added Portuguese translation
Fixed keyerror on user setting page

Fix #891
Rework of the projector with websocket

* 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
Merge pull request #889 from ostcar/projector

Rework of the projector with websocket
Merge pull request #892 from ostcar/issue-891

Fixed keyerror on user setting page
Added Feature for config app, to return the default value for a key
Merge pull request #893 from ostcar/back_to_default_config

Added Feature for config app, to return the default value for a key
Merge remote-tracking branch 'openslides/stable/1.4.x'

Conflicts:
	AUTHORS
Rework (projector) template with bootstrap.

- 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.
Merge pull request #901 from emanuelschuetze/newprojectortemplate

Rework projector template with bootstrap
More projector fixtures

* Update projector when polls are updated.
* Update projector when assignment candidates are updated
* Update projector when motion submitter are updated
* Fixed the assignment publish poll view
* Added projector.api.register_slide_model
Merge pull request #899 from ostcar/projector

Added projector.api.register_slide_model