Merge pull request #905 from emanuelschuetze/projector-fixes

Fixes and improvements for projector and template
Cleaned up utils
Merge pull request #895 from ostcar/utils

Cleaned up utils
Add prototype of full text search integration in openslides
Allow for empty title and text body, fix pep8 errors
Full text search with haystack and whoosh.

Updated THANKS file.
Portable: Added haystack and whoosh.