Spanish sample texts

Hi s9yobena!

This is my first pull request ever.

I've just added two longer sample files for Spanish language (sample-text4.freeling and sample-text5.freeling). They are real texts, in plain text, annotated with FreeLing tagset and follow this format:
one token per line (each line contains separated by tabs: word form, POS, lemma)
\n\n to indicate sentence boundary

I think that this examples will help us to test better ml-translationese for Spanish. Moreover, they include to features: sentence boundary and more positional attributes (something that can appear or not).

Best!

jmmtra