"use strict" for all frontend files (backend was done earlier)

public/javascripts/dialogs/add_link.js

@@ -1,3 +1,5 @@
+"use strict";
+
 const addLink = (function() {
     const dialogEl = $("#insert-link-dialog");
     const formEl = $("#insert-link-form");

public/javascripts/dialogs/event_log.js

@@ -1,3 +1,5 @@
+"use strict";
+
 const eventLog = (function() {
     const dialogEl = $("#event-log-dialog");
     const listEl = $("#event-log-list");

public/javascripts/dialogs/jump_to_note.js

@@ -1,3 +1,5 @@
+"use strict";
+
 const jumpToNote = (function() {
     const dialogEl = $("#jump-to-note-dialog");
     const autoCompleteEl = $("#jump-to-note-autocomplete");

public/javascripts/dialogs/note_history.js

@@ -1,3 +1,5 @@
+"use strict";
+
 const noteHistory = (function() {
     const dialogEl = $("#note-history-dialog");
     const listEl = $("#note-history-list");

public/javascripts/dialogs/recent_changes.js

@@ -1,3 +1,5 @@
+"use strict";
+
 const recentChanges = (function() {
     const dialogEl = $("#recent-changes-dialog");
 

public/javascripts/dialogs/recent_notes.js

@@ -1,3 +1,5 @@
+"use strict";
+
 const recentNotes = (function() {
     const dialogEl = $("#recent-notes-dialog");
     const selectBoxEl = $('#recent-notes-select-box');

public/javascripts/dialogs/settings.js

@@ -1,3 +1,5 @@
+"use strict";
+
 const settings = (function() {
     const dialogEl = $("#settings-dialog");
     const tabsEl = $("#settings-tabs");