Add unbounid support in xml

Add unbounid support in xml

Fixes gh-6011

docs/manual/src/docs/asciidoc/_includes/servlet/additional-topics/ldap.adoc

@@ -47,6 +47,8 @@ This can be configured to point at an external LDAP server, using the `url` attr
 <ldap-server url="ldap://springframework.org:389/dc=springframework,dc=org" />
 ----
 
+NOTE: `spring-security` provides integration with `apacheds` and `unboundid` as a embedded ldap servers. You can choose between them using the attribute `mode` in `ldap-server`.
+
 ==== Using an Embedded Test Server
 The `<ldap-server>` element can also be used to create an embedded server, which can be very useful for testing and demonstrations.
 In this case you use it without the `url` attribute:

docs/manual/src/docs/asciidoc/_includes/servlet/appendix/namespace.adoc

@@ -2360,6 +2360,9 @@ This is actually the bean `id` of the `ContextSource` instance, if you want to u
 [[nsa-ldap-server-attributes]]
 ===== <ldap-server> Attributes
 
+[[nsa-ldap-server-mode]]
+* **mode**
+Explicitly specifies which embedded ldap server should use. Values are `apacheds` and `unboundid`. By default, it will depends if the library is available in the classpath.
 
 [[nsa-ldap-server-id]]
 * **id**

docs/manual/src/docs/asciidoc/index.adoc

@@ -1,5 +1,5 @@
 = Spring Security Reference
-Ben Alex; Luke Taylor; Rob Winch; Gunnar Hillert; Joe Grandja; Jay Bryant
+Ben Alex; Luke Taylor; Rob Winch; Gunnar Hillert; Joe Grandja; Jay Bryant; Eddú Meléndez
 :include-dir: _includes
 :security-api-url: https://docs.spring.io/spring-security/site/docs/current/api/
 :source-indent: 0