Support Groovy Markup templating in Spring MVC

This commit adds support for Groovy templating, available as of
Groovy 2.3.1.

To enable this, one should create a new GroovyMarkupViewResolver
and a new GroovyMarkupConfigurer Beans in their application context.

```
    // Add that bean definition in a @Configuration class
    @Bean
    public GroovyMarkupConfig groovyMarkupConfigurer() {

      GroovyMarkupConfigurer configurer = new GroovyMarkupConfigurer();
      configurer.setResourceLoaderPath("classpath:/WEB-INF/groovymarkup/");
      return configurer;
    }
```

Issue: SPR-11789