Fixes comments from review.

Adds a safe check, i18n is expecting undefined not null. Fix a method name and translation to be at placeholder.

modules/UI/feedback/FeedbackWindow.js

         this.submitted = false;
         this.onCloseCallback = function() {};
 
-        this.setDefaulOptions();
+        this.setDefaultOptions();
     }
 
-    setDefaulOptions() {
+    setDefaultOptions() {
         var self = this;
 
         this.options = {

modules/UI/invite/InviteDialogView.js

                </label>
                 <div class="input-control__container">
                     <input class="input-control__input" id="newPasswordInput"
-                           type="text" data-i18n="dialog.createPassword">
+                           type="text" 
+                           data-i18n="[placeholder]dialog.createPassword">
                     <button id="addPasswordBtn" id="inviteDialogAddPassword"
                             disabled data-i18n="dialog.add"
                             class="button-control button-control_light">

modules/translation/translation.js

         return i18n.lng();
     },
     translateElement: function (selector, options) {
-        selector.i18n(options);
+        // i18next expects undefined if options are missing, check if its null
+        selector.i18n(
+            options === null ? undefined : options);
     },
     generateTranslationHTML: function (key, options) {
         var str = "<span data-i18n=\"" + key + "\"";
             str += " data-i18n-options='" + JSON.stringify(options) + "'";
         }
         str += ">";
-        str += i18n.t(key, options);
+        // i18next expects undefined if options ARE missing, check if its null
+        str += i18n.t(key, options === null ? undefined : options);
         str += "</span>";
         return str;