Remove ES6 arrow functions from hover-box

Browsers such as Safari do not natively understand ES6 functions, thus during development only Chrome can be used when the hover box is imported into the page.
(On Safari the following error occurs: ```SyntaxError: Unexpected token ')'
appendChild — index.html:77
hoverBox — template.v1.js:18012
renderOnLoad — template.v1.js:18217
(anonymous function) — template.v1.js:18227
```, this is caused by the function arrow notation not being parsed).

components/hover-box.txt

@@ -74,7 +74,7 @@ DtHoverBox.prototype.extendTimeout = function extendTimeout(T) {
   //console.log("extend", T)
   var this_ = this;
   this.stopTimeout();
-  this.timeout = setTimeout(() => this_.hide(), T);
+  this.timeout = setTimeout(function(){this_.hide();}.bind(this), T);
 }
 
 // Bind events to a link to open this box
@@ -83,13 +83,14 @@ DtHoverBox.prototype.bind = function bind(node) {
     node = document.querySelector(node);
   }
 
-  node.addEventListener("mouseover", () => {
+  node.addEventListener("mouseover", function(){
     if (!this.visible) this.showAtNode(node);
     this.stopTimeout();
-  });
-  node.addEventListener("mouseout", () => this.extendTimeout(250) );
+  }.bind(this));
 
-  node.addEventListener("touchstart", e => {
+  node.addEventListener("mouseout", function(){this.extendTimeout(250);}.bind(this));
+
+  node.addEventListener("touchstart", function(e) {
     if (this.visible) {
       this.hide();
     } else {
@@ -97,26 +98,26 @@ DtHoverBox.prototype.bind = function bind(node) {
     }
     // Don't trigger body touchstart event when touching link
     e.stopPropagation();
-  });
+  }.bind(this));
 }
 
 DtHoverBox.prototype.bindDivEvents = function bindDivEvents(){
   // For mice, same behavior as hovering on links
-  this.div.addEventListener("mouseover", () => {
+  this.div.addEventListener("mouseover", function(){
     if (!this.visible) this.showAtNode(node);
     this.stopTimeout();
-  });
-  this.div.addEventListener("mouseout", () => this.extendTimeout(250) );
+  }.bind(this));
+  this.div.addEventListener("mouseout", function(){this.extendTimeout(250);}.bind(this));
 
   // Don't trigger body touchstart event when touching within box
-  this.div.addEventListener("touchstart", e => e.stopPropagation());
+  this.div.addEventListener("touchstart", function(e){e.stopPropagation();});
   // Close box when touching outside box
-  document.body.addEventListener("touchstart", () => this.hide());
+  document.body.addEventListener("touchstart", function(){this.hide();}.bind(this));
 }
 
 var hover_es = document.querySelectorAll("span[data-hover-ref]");
 hover_es = [].slice.apply(hover_es);
-hover_es.forEach((e,n) => {
+hover_es.forEach(function(e,n){
   var ref_id = e.getAttribute("data-hover-ref");
   DtHoverBox.get_box(ref_id).bind(e);
 })