Add change location support

Based on this question https://github.com/caelum/vraptor-i18n/issues/1 PR creates the initial internationalization support via jstl.

You can disable the environment via two features, which are:
  - Setting via parameter (_locale), default true
  - Setting via web browser, default false

I used an interceptor because extending the RequestHandlerObserver will broke applications that extend it.

I did not do the issue of validate if has the resource of language because in testing, I realized that Java uses the default if not valid and need help if necessary, I don't know the best way to get this information from vraptor.

I'm waiting any suggestions to improve the code quality.
In that case, if someone create a observer of a previous event of vraptor and use localization features it would not use the right locale.
Maybe you should customize the component that's producing the resource bundle...