Add optional XML declaration to pidprinter

Refs #11812
import inetref from xmltv into program guide

see http://xmltv.cvs.sourceforge.net/viewvc/xmltv/xmltv/xmltv.dtd?r1=1.45&r2=1.46
currently the expectation is that also a category "series" or "movie" is
present and for series an xmltv_ns episode number