New XML tag syntax to invoke templates

Supports `<tone:header title="MyTitle" />` as an alias to `<% use(header.class).render("MyTitle"); %>`.

Very simple implementation, regex-based. Only supports String parameters, with everything optional, and one code block (tag body).

/cc @guilhermesilveira @mauricioaniche 
Would be something like this, I guess:
```
Stream.of(listeners).reduce(content, (contentAcumuladoMaluco, next) -> next.preprocess(content), (_, contentDepois) -> contentDepois);
```