integrate feedback from IICO Team

+ remove related_links (unused)
+ remove get_object (unused)
+ explicitly call ::RailsConnector::Obj to make clear where this superclass comes from
+ deactive Publication
+ introduce Container
+ use naming scheme for Page and Box object classes
+ allow to set title and type of object classes in the generators
+ add footer cell
+ refactor workspace toggle
+ rename _meta to _configuration
+ fix: show_in_navigation
+ fix: error_page/index