FIx unrecoverable errors when using IE11

www/common/cursor.js

@@ -81,7 +81,7 @@ define([
                         var path = [];
                         while (current !== element) {
                             path.unshift(current);
-                            current = current.parentElement;
+                            current = current.parentNode;
                         }
 
                         if (current === element) { // Should always be the case

www/common/sframe-chainpad-netflux-outer.js

@@ -59,7 +59,7 @@ define([], function () {
                     var id = '';
                     if (window.nacl) {
                         var hash = window.nacl.hash(window.nacl.util.decodeUTF8(msg));
-                        id = window.nacl.util.encodeBase64(hash.slice(0, 8)) + '|';
+                        id = window.nacl.util.encodeBase64(hash.subarray(0, 8)) + '|';
                     } else {
                         console.log("Checkpoint sent without an ID. Nacl is missing.");
                     }

www/pad/cursor.js

@@ -40,9 +40,9 @@ define([
 
         var makeCursor = function (id, cursor) {
             if (cursors[id]) {
-                cursors[id].el.remove();
-                cursors[id].elstart.remove();
-                cursors[id].elend.remove();
+                $(cursors[id].el).remove();
+                $(cursors[id].elstart).remove();
+                $(cursors[id].elend).remove();
             }
             cursors[id] = {
                 el: $('<span>', {
@@ -68,9 +68,9 @@ define([
         };
         var deleteCursor = function (id) {
             if (!cursors[id]) { return; }
-            cursors[id].el.remove();
-            cursors[id].elstart.remove();
-            cursors[id].elend.remove();
+            $(cursors[id].el).remove();
+            $(cursors[id].elstart).remove();
+            $(cursors[id].elend).remove();
             delete cursors[id];
         };