[PATCH] v2 pt_PO.pt

[Fernando]

This patch supersedes my previous patch sent to wine-patches on 2018-12-26, which was pending due to lack of "authorship", and can be discarded.

I translated all the changes tagged "fuzzy", plus some empty translations, plus several corrections.

I have added some comments at the top of the file to indicate some translations used to help with future consistency.

I have filled in the field last-translator in pt_PT.po and added the header signed-off to the patch.

I hope all is well. For feedback, it would be better if you address my email directly.

Regards and best wishes to 2018.
Fernando Martins