Template:Showfacts set ancestors/upshift ahn

Purpose: Given a ahnentafel number, this function upshifts it to the next generation.

Example: Ahn value 2 (father) becomes 4 if the source was the father of the father of the subject. This function upshifts it to 6 if the relation was father of the mother.

Tecnical notes

 * for mother side, add one