Comment out NasaImageExchange federated search
added 'django.middleware.http.ConditionalGetMiddleware' to MIDDLEWARE_CLASSES to support client side browser caching
fix artstor results breaking because nasa search was removed
re-fix lack of csrf token on rooibos/solr/templates/results.html form
fix for EncodingError at /viewers/packagefilesviewer/ - used django's smart_str()
more fixes for file names (and back to ascii codec) in presentation/viewers.py