adding more polyfill goodness for firefox

ext/bg/js/gecko.js

@@ -1,5 +1,3 @@
-console.log('blah');
-
 //
 // Gecko does not currently support chrome.storage.sync, use storage.local instead
 // https://bugzilla.mozilla.org/show_bug.cgi?id=1220494

ext/fg/frame.html

@@ -13,6 +13,7 @@
         <div class="content"></div>
 
         <script src="../lib/jquery-2.2.2.min.js"></script>
+        <script src="js/gecko.js"></script>
         <script src="js/util.js"></script>
         <script src="js/frame.js"></script>
     </body>

ext/fg/js/gecko.js

@@ -0,0 +1,12 @@
+if (!document.caretRangeFromPoint){
+    document.caretRangeFromPoint = function polyfillcaretRangeFromPoint(x,y){
+        let range = document.createRange();
+        let position = document.caretPositionFromPoint(x,y);
+        if (!position) {
+            return null;
+        }
+        range.setStart(position.offsetNode, position.offset);
+        range.setEnd(position.offsetNode, position.offset);
+        return range;
+    };
+}