Update metadata and setup.py for new plugin api.
Move plugin to new apis of OpenSlides 1.6a1

Rework of slides, urls, views, widget and main menu entry.
Many small styling changes.
Add winners to result view and slide.
Added list of all results for print.
Used absolute_url filter instead of model_url tag.
Added csv import
Update English language file
Updated to final OpenSlides 1.6.

Also used CSVImportView and updated metadata.
Updated English language file.
Merge pull request #14 from normanjaeckel/CSV_Import

Update to OpenSlides 1.6.