Template:Set ahn/doc

Purpose: sets the Property:Ahnentafel to the current article plus a merge of the Ahnentafel trees of the subject's two parents.


 * Notes on flow:


 * 1) set own ahn value( #1 ) to pagename
 * 2) grab the parents' ahnan string if any and convert to this generation.


 * Note that this ahnan string is the same for all children of these two parents.