Handling ValidationExceptions in interceptors

Please do not merge it yet, it's a work in progress related with #858 

My idea here is to extract classes to better deal with exception handling so then we could reuse the exception handling code to develop that  `@ValidationInterceptor ` feature that @lucascs proposed.

I've implemented a `Try` class, similar to the scala's Try monad. Is not a proper monad here, but I think it's a nice abstraction to handle exceptions, what do you think? @lucascs @Turini @garcia-jj 
May be `null` is better than this exception, because 

1) Success means that have no exception, so return null is right;

2) in the view we can do something like `${not empty try.exception}`. If this exception we need to write more code: `${try.failed ? try.exception : null}`;