ref #6925 Fix part initialisation for open handlers
ref #6598 Migrate "Open in.." handlers
ref #6932 Remove unused code
ref #6932 Migrate marker type handler
ref #6932 Asjust menu item visibility
ref #6932 Migrate merge handlers
ref #6932 Refactor merge and delete handler
ref #6932 Refactor merge annotating
ref #6932 Ask before permanent delete
ref #6932 further migration of handlers
ref #6932 Fix new element handler and save
ref #6932 Fix intitial layouting of bulk editor
ref #6932 Migrate bulk editor handlers and add annotation merge support
ref #6932 Migrate bulk editor handlers (part I)
ref #6932 Migrate bulk context menu (non-functional)
ref #6932 Migrate bulk editor (search and results display working)
ref #6932 Migrate bulk editor (non-stable)