build: add "subdir-objects" option in configure.ac
build: add "subdir-objects" option in configure.ac

MathieuDuponchelle/grilo-plugins,jasuarez/grilo-plugins,MathieuDuponchelle/grilo-plugins,GNOME/grilo-plugins,MathieuDuponchelle/grilo-plugins,grilofw/grilo-plugins,jasuarez/grilo-plugins,grilofw/grilo-plugins,MikePetullo/grilo-plugins,MikePetullo/grilo-plugins,MikePetullo/grilo-plugins,MathieuDuponchelle/grilo-plugins,GNOME/grilo-plugins