Added issue comment and close issue feature

src/js/persistent-ops.js

@@ -0,0 +1,29 @@
+module.exports = class PersistentOps {
+    getLatestComment(comments) {
+        if(comments && comments.length > 0)
+            return comments[comments.length - 1]['body'];
+    }
+
+    setCookie(cname, cvalue, exdays) {
+        var d = new Date();
+        d.setTime(d.getTime() + (exdays*24*60*60*1000));
+        var expires = "expires="+ d.toUTCString();
+        document.cookie = cname + "=" + cvalue + ";" + expires + ";path=/";
+    }
+
+    getCookie(cname) {
+        var name = cname + "=";
+        var decodedCookie = decodeURIComponent(document.cookie);
+        var ca = decodedCookie.split(';');
+        for(var i = 0; i <ca.length; i++) {
+            var c = ca[i];
+            while (c.charAt(0) == ' ') {
+                c = c.substring(1);
+            }
+            if (c.indexOf(name) == 0) {
+                return c.substring(name.length, c.length);
+            }
+        }
+        return "";
+    }
+}