Optimizing check in templates if user is logged in.
Annotations can reference collections as well.
When displaying references, use our reference text.

See #119 for more information about how user will be able to make
references. To teach them we want to display references to entities in
the same way all around.
List all annotation references in meta menu.
Give user feedback if link is internal.

Especially don't say that it is an error to link to some our page
without and ID.
When closing link dialog reselect editor back.
Removed old code from person page.
Clicks on links while editing should not do anything.