spring related updates

1) scan package for config classes rather than manually registering them one by one. this will make implementing extensions easier without changing / touching the core of SteVe
2) EnableWebSecurity replaces the deprecated EnableWebMvcSecurity

Author: goekay

src/main/java/de/rwth/idsg/steve/SteveAppContext.java

@@ -1,9 +1,5 @@
 package de.rwth.idsg.steve;
 
-import de.rwth.idsg.steve.config.BeanConfiguration;
-import de.rwth.idsg.steve.config.OcppConfiguration;
-import de.rwth.idsg.steve.config.SecurityConfiguration;
-import de.rwth.idsg.steve.config.WebSocketConfiguration;
 import org.apache.cxf.Bus;
 import org.apache.cxf.BusFactory;
 import org.apache.cxf.common.logging.LogUtils;
@@ -42,10 +38,7 @@ public class SteveAppContext {
 
     public SteveAppContext() {
         springContext = new AnnotationConfigWebApplicationContext();
-        springContext.register(BeanConfiguration.class);
-        springContext.register(OcppConfiguration.class);
-        springContext.register(SecurityConfiguration.class);
-        springContext.register(WebSocketConfiguration.class);
+        springContext.scan("de.rwth.idsg.steve.config");
     }
 
     public HandlerCollection getHandlers() throws IOException {

src/main/java/de/rwth/idsg/steve/config/SecurityConfiguration.java

@@ -6,15 +6,15 @@
 import org.springframework.security.config.annotation.authentication.builders.AuthenticationManagerBuilder;
 import org.springframework.security.config.annotation.web.builders.HttpSecurity;
 import org.springframework.security.config.annotation.web.builders.WebSecurity;
+import org.springframework.security.config.annotation.web.configuration.EnableWebSecurity;
 import org.springframework.security.config.annotation.web.configuration.WebSecurityConfigurerAdapter;
-import org.springframework.security.config.annotation.web.servlet.configuration.EnableWebMvcSecurity;
 
 /**
  * @author Sevket Goekay <goekay@dbis.rwth-aachen.de>
  * @since 07.01.2015
  */
 @Configuration
-@EnableWebMvcSecurity
+@EnableWebSecurity
 public class SecurityConfiguration extends WebSecurityConfigurerAdapter {
 
     @Autowired