JASPIAuthenticationInfo must override merge in order to merge the login-module stacks

JASPIAuthenticationInfo currently inherits the merge method from BaseSecurityInfo. As a result, the login-module-stacks are lost during the merge process because the inherited merge implementation creates a new instance of JASPIAuthenticationInfo that contains only the merged auth-modules. To avoid this we must override the merge method in JASPIAuthenticationInfo to make sure the login-module-stacks are also merged in the final object.

Also, the ApplicationPolicy should not allow the merge of authentication and authentication-jaspi methods, as only one of the configurations is allowed per policy. This means that a verification is needed in order to make sure that a policy doesn't extend a parent policy that specifies a different type of authentication.