Add app name to popup, use fully-qualified URL for popupUri

Author: dan-f

common/popup.html

@@ -4,7 +4,7 @@
     <link type="text/css" rel="stylesheet" href="https://linkeddata.github.io/solid-app-set/style/tabbedtab.css" />
     <script>
       var $SOLID_GLOBAL_config = {
-        popupUri: '/common/popup.html'
+        popupUri: window.location.origin + '/common/popup.html'
       }
     </script>
     <script type="text/javascript" src="https://linkeddata.github.io/mashlib/dist/mashlib.min.js"></script>