build: Port from gnome-autogen.sh to a stand-alone autogen.sh
build: Port from gnome-autogen.sh to a stand-alone autogen.sh

This drops our dependency on gnome-common.

MathieuDuponchelle/uhttpmock,Distrotech/uhttpmock,MathieuDuponchelle/uhttpmock,pwithnall/uhttpmock,pwithnall/uhttpmock,Distrotech/uhttpmock,MathieuDuponchelle/uhttpmock