PoGenerator: generate LocalizationMetadata as a PO header
PoGenerator: generate LocalizationMetadata as a PO header

Fill in required PO header fields if they are
not present in LocalizationMetadata

rdio/vernacular,rdio/vernacular,mightea/vernacular,mightea/vernacular,gabornemeth/vernacular,benoitjadinon/vernacular,benoitjadinon/vernacular,StephaneDelcroix/vernacular,StephaneDelcroix/vernacular,gabornemeth/vernacular,dsuess/vernacular,dsuess/vernacular