Update NEWS, release 2.17.0
Update NEWS, release 2.17.0

davidmalcolm/pygobject,thiblahute/pygobject,jdahlin/pygobject,GNOME/pygobject,davibe/pygobject,davidmalcolm/pygobject,MathieuDuponchelle/pygobject,alexef/pygobject,Distrotech/pygobject,pexip/pygobject,nzjrs/pygobject,pexip/pygobject,GNOME/pygobject,sfeltman/pygobject,thiblahute/pygobject,davibe/pygobject,jdahlin/pygobject,sfeltman/pygobject,Distrotech/pygobject,Distrotech/pygobject,choeger/pygobject-cmake,GNOME/pygobject,MathieuDuponchelle/pygobject,davidmalcolm/pygobject,alexef/pygobject,nzjrs/pygobject,choeger/pygobject-cmake,davibe/pygobject,MathieuDuponchelle/pygobject,alexef/pygobject,choeger/pygobject-cmake,pexip/pygobject,thiblahute/pygobject,nzjrs/pygobject,davibe/pygobject,Distrotech/pygobject,sfeltman/pygobject,jdahlin/pygobject