bugs fixed for standalone volumes; zoom added

views/layout.pug

@@ -23,6 +23,10 @@ html
             label(for="upload") upload data
             input(type="file", name="upload")#upload
       div#info
+        div#zoom
+          a#zoomin 🔎+
+          a#zoomreset 0
+          a#zoomout -🔍
         div#orientation
         div#clock= (new Date()).toLocaleString()
         div#status.error