Added extras menu, stubbed map editor, made asset viewer and map editor accessible from extras menu

lib/tools/asset_viewer/lib/main_menu.rb

@@ -18,6 +18,10 @@ class IMICFPS
 
         @manifests.sort_by! { |m| m.name.downcase }
 
+        button "Back", margin_bottom: 25 do
+          pop_state
+        end
+
         flow(margin: 10) do
           @manifests.each do |manifest|
             button manifest.name do
@@ -25,10 +29,6 @@ class IMICFPS
             end
           end
         end
-
-        button "Exit", margin_top: 25 do
-          window.close
-        end
       end
 
       def update