Added support for issue #3 updates 

Ive made a pull request: https://github.com/AlxMedia/hueman/pull/25
and this pl_PL file will be ok AFTER Alx accept this pull. 

added: valid plural forms for polish - if you want to edit this file in poedit please DON`T CHANGE it. Because standard plural for pl_PL doesn`t have a valid form for null -> "0 komentarze" instead of "0 komentarzy".

added: valid forms for comments and trackbacks [komentarze i odniesienia]