Simplify #new and #create in Admin::ContentController
Factor out access control for edit and update actions
Clean up Admin::ContentController#edit
Clean up Admin::ContentController#update
Reduce use of get_or_build_article and move it to controller
Small cleanup of #autosave
Remove specs for removed Article#get_or_build
Fix spec for Content#text_filter
Make :user factory consistent

If users have a text-filter, they use the simple editor
Fix Admin::PagesController specs