feat(editor): more models selected at once (Shift+LMB), moved and turned by the gizmo together, undone in one step; Ctrl+C / Ctrl+V copy the selected models with their groups and paste them at the cursor; Ctrl+G groups the selection, Ctrl+Shift+G takes a group apart, groups written to the scenery as group ... endgroup and loaded as groups of their own; End drops each model of the selection and of their groups onto the ground; menu of the selection at the cursor on Ctrl+RMB; Edit menu with undo, redo, the clipboard, grouping, deleting; Help > Keyboard shortcuts (F1) with the keys of every field of work, F2-F5 choose the fields of work, the tracks menu lists the track tools with their keys, the keys and descriptions in the menus and tooltips; self-test commands for the selection; Polish translation

application/editoruilayer.cpp

@@ -972,6 +972,8 @@ void editor_ui::render_menu_contents()
 		}
 		ImGui::EndMenu();
 	}
+	if (m_editmenu)
+		m_editmenu();
 
 	ui_layer::render_menu_contents();