OpenSlides protocol plugin 2.0 (WIP)

[FinnStutzenstein]

@emanuelschuetze Just play a bit around..

Info: This does not work with current OpenSlides master. Please checkout my branch 'PluginDev' to run OS.

[FinnStutzenstein]

Todos if this base commit is merged:

• [ ] Add tests
• [ ] Make the layout prettier and include more features
• [ ] Translate everything
• [ ] Make a nicer hook to append staticfiles