Added custom slide projector element class.
Added welcome slide as custom slide.
Added user slide projector element class.
Added clock, countdown ans message projector elements.
Renamed SignalConnectMetaClass classmethod get_all_objects to get_all (private API).
Added migrations to core app.
Fixed and wrote tests.
Updated CHANGELOG.
- Fixed js error on dashboard page if no cookie is found.
- Use cookies only until end of session. For dashboard cookies use url /dashboard only.
- Updated permission numbering of builtin groups and added can_use_chat permission.
- Used minified version of jquery.cookie.
- Added TODO comment for django session way from pull request.