Rename URL parameter from task_id to pk for class-based views.
Replace tinymce wysiwyg editor with ckeditor.
Fix UserMixin for class based views: set user after form saving, not during form save.
Remove UserMixin from forms.
Allow save Task and TaskInfo with unset user field.
Remove TinyMCE and Grapelli urlpatterns (they were not removed, when modules where removed.