add descrption to all content, caption to images
implement searchbox from two.bootstrap
access child directly by slug
add is_visible to default workflow
include handler, request in template-specific context generation
enlarge all fields
print actual state; fixes #568
start implementing #569
issue #540 improvement: link to contents in crumbs
emphasize that it's about properties, not other types of 'contents'
initial implementation of deletion - issue #484
stick with american english for now
functional toggle-all button