SEC-2517: Add easy integration with ajax rest api

Lukasz Strzelecki (Migrated from SEC-2517) said:

I want in easy way to configure loggin through json api.

I want send & receive application/json Content-Type through http.

 @Override
    protected void configure(HttpSecurity http) throws Exception {
        http
                .ajaxLogin()
                .loginProcessingUrl("/login")
                .successHandler()
                .failureHandler()
                .usernamePropertyName("username")
                .passwordPropertyName("password")
                .and()
                .logout()
                .logoutUrl("/logout")
                .logoutSuccessHandler()
                .deleteCookies("JSESSIONID")

    }

Start by reviewing the HttpSecurity configuration example and the requested ajaxLogin(), logout(), successHandler(), and failureHandler() entry points. Clarify the intended JSON request and response behavior, handler APIs, and authentication flow before identifying the relevant Spring Security implementation and tests. Done should mean the requested JSON login and logout integration is specified, implemented, and covered by tests.