Fix missing url_name_args = [] lines in different views.

Fix custom slide create and update view.
Fix motion category create and update view.
Merge pull request #935 from normanjaeckel/UrlNameArgs

Fix missing url_name_args = [] lines in different views.
Updated EN djanog.po file.
Merge pull request #936 from emanuelschuetze/translation

Updated EN djanog.po file.
Updated EN + DE translation file.
Updated requirements.
Used reportlabs qrcode widget (instead of extra qrcode package).
Merge pull request #937 from emanuelschuetze/translation

Updated EN + DE translation file.
Merge pull request #933 from emanuelschuetze/requirements

Requirements
Fix url_name_args bug.

Fix delete view for motion categories. Add test for custom slide delete view.
Updated Changelog for 1.5b1
Merge pull request #942 from emanuelschuetze/changelog

Updated Changelog for 1.5b1
Merge pull request #941 from normanjaeckel/UrlNameArgsFix

Fix url_name_args bug.
Fix #934: Error in motion import with bad csv file.
Change link in install instruction (Setuptools). Fix #949.
Merge pull request #950 from normanjaeckel/Fix949

Change link in install instruction (Setuptools). Fix #949.
Merge pull request #946 from normanjaeckel/FixImport

Fix #934: Error in motion import with bad csv file.
Improved projector zoom and scroll behaviour.

Zoom and scroll the full content div (incl. title and sidebar).
Add zoom and scroll level in projector live view widget.
Fixed portable build error for pillow package. Updated create_portable.txt.
Add message if someone adds himself to the list of speakers. Fix #927.