big refactoring: classes related to login

src/main/java/de/deadlocker8/budgetmaster/controller/LoginController.java → src/main/java/de/deadlocker8/budgetmaster/authentication/LoginController.java

-package de.deadlocker8.budgetmaster.controller;
+package de.deadlocker8.budgetmaster.authentication;
 
+import de.deadlocker8.budgetmaster.controller.BaseController;
 import org.joda.time.DateTime;
 import org.springframework.security.web.savedrequest.DefaultSavedRequest;
 import org.springframework.stereotype.Controller;