Return input when linking a BBS, some consistent instantiation of <form>, more work on select2 transition

app/Http/Controllers/UserController.php

@@ -64,7 +64,9 @@ class UserController extends Controller
 					'code', 'Invalid Code!'
 				);
 
-				return back()->withErrors($validator);
+				return back()
+					->withInput()
+					->withErrors($validator);
 			}
 		}