v3: several fixes to class system, move /logout outside of api

test/api/v3/integration/user/POST-user_change-class.test.js

@@ -6,7 +6,10 @@ describe('POST /user/change-class', () => {
   let user;
 
   beforeEach(async () => {
-    user = await generateUser();
+    user = await generateUser({
+      'flags.classSelected': false,
+      'stats.lvl': 10,
+    });
   });
 
   // More tests in common code unit tests

test/api/v3/integration/user/PUT-user.test.js

@@ -57,6 +57,7 @@ describe('PUT /user', () => {
       'flags unless whitelisted': {'flags.dropsEnabled': true},
       webhooks: {'preferences.webhooks': [1, 2, 3]},
       sleep: {'preferences.sleep': true},
+      'disable classes': {'preferences.disableClasses': true},
     };
 
     each(protectedOperations, (data, testName) => {