app: automatically load resources from base path

We don't have to load most of the menus we're currently loading
by using the very handy automatic resource loading.

This patch fixup so the app loads resources automagically.

data/ui/menus.ui

@@ -1,6 +1,6 @@
 <?xml version="1.0"?>
 <interface>
-  <menu id="appmenu">
+  <menu id="app-menu">
     <section>
       <item>
         <attribute name="label" translatable="yes">Add Eve_nt…</attribute>
@@ -25,7 +25,7 @@
       </item>
     </section>
   </menu>
-  <menu id="winmenu">
+  <menu id="win-menu">
     <section>
       <item>
         <attribute name="label" translatable="yes">Add Eve_nt…</attribute>