Fixed non-working Spanish validator translation

This translation contains translation keys from the ZF1 validators *NOT* the ZF2 ones. This effectively renders them useless since most of the ZF2 translation keys have changed. 

I updated all the translations so that they work with ZF2 and also corrected a few grammatical errors and typos.
Fixed translation based on Maks3w's comments
Merge remote-tracking branch 'upstream/master'
Merge pull request #5557