Merge pull request #611 from emanuelschuetze/Issue543

Sorting agenda items with nestedSortable.
Fixed saving anonymous user in a PersonField
A lot of template improvements and translation fixes

- Fixed agenda widget for special slide views (e.g. list of speakers, summary).
- Fixed back to motion(s) link
- Set icon for list of speakers widget.
- Fixed overlay widget layout of form elements.
- Added submenu with other config_pages to version.html.
- Updated completly DE translations, fixed EN strings.
- Coding style: Use correct ugettext and ugettext_lazy strings. Use "as _" for ugettext only.
Updated translation.
- Improved projector template (clock image, fixed facicon, added subtitle for list of speakers)
- Changed permission strings ('oneself'). Added check if group(pk=3) exists.
- Added event name and description to base template. Some minor template layout fixes.
- Use static subtile (no context var). Show last 2 old_speakers for projector.
- Cut old_speakers.
- Projektor template style changes (e.g. overlay list of speakers).