Initial work to reorder zoom fields.

src/libs/document-uid.js

@@ -0,0 +1,9 @@
+/**
+ * A unique id for the current document.
+ */
+let REF = 0;
+
+export default function(prefix="") {
+  REF++;
+  return prefix+REF;
+}

src/libs/sort-numerically.js

@@ -0,0 +1,14 @@
+export default function(a, b) {
+  a = parseFloat(a, 10);
+  b = parseFloat(b, 10);
+
+  if(a < b) {
+    return -1
+  }
+  else if(a > b) {
+    return 1
+  }
+  else {
+    return 0;
+  }
+}