Use xml / javaconfig folders for samples

Fixes gh-3752

samples/xml/contacts/client/client.properties

@@ -0,0 +1,8 @@
+# Properties file with server URL settings for remote access.
+# Applied by PropertyPlaceholderConfigurer from "clientContext.xml".
+#
+
+serverName=localhost
+httpPort=8080
+contextPath=/spring-security-sample-contacts-filter
+rmiPort=1099