[FINISHED 84295650] In portal - heading "Slovensky zvaz hadzanej" added right padding.
[FINISHED 84294064] Portal editor - default value for publish date is today.
[FINISHED #84106192]
Portal - paging of articles in a category (in both portal and portal editor).
Plus option to set the page size in category definition.
Manglers: Unique mangler initial
[FINISHED #74521434] Check Unique Values

 - values marked $unique:true are check during save phase.
[FINISHED #84188504] Schema extends.

-- modified schema-constants -> schemas must be refactored.