Expose default security configuration

Closes spring-projectsgh-110

Author: jgrandja

oauth2-authorization-server/src/main/java/org/springframework/security/config/annotation/web/configuration/OAuth2AuthorizationServerSecurity.java

@@ -33,9 +33,13 @@
 @Order(Ordered.HIGHEST_PRECEDENCE)
 public class OAuth2AuthorizationServerSecurity extends WebSecurityConfigurerAdapter {
 
-	// @formatter:off
 	@Override
 	protected void configure(HttpSecurity http) throws Exception {
+		applyDefaultConfiguration(http);
+	}
+
+	// @formatter:off
+	public static void applyDefaultConfiguration(HttpSecurity http) throws Exception {
 		OAuth2AuthorizationServerConfigurer<HttpSecurity> authorizationServerConfigurer =
 				new OAuth2AuthorizationServerConfigurer<>();
 		RequestMatcher[] endpointMatchers = authorizationServerConfigurer