build: Unescape conditionally defined defaults in AS_HELP_STRING
build: Unescape conditionally defined defaults in AS_HELP_STRING

AS_HELP_STRING() escapes everything, so m4 doesn't have a chance to run
expansions.

collects/clutter,collects/clutter,ebassi/clutter,ebassi/clutter,djdeath/clutter,djdeath/clutter-android,djdeath/clutter-multithreaded,GNOME/clutter,spatulasnout/clutter,spatulasnout/clutter,djdeath/clutter,spatulasnout/clutter,Distrotech/clutter,heysion/clutter-clone,jigpu/clutter,Distrotech/clutter,djdeath/clutter-android,djdeath/clutter,djdeath/clutter-android,ebassi/clutter,djdeath/clutter-multithreaded,spatulasnout/clutter,djdeath/clutter,Distrotech/clutter,jigpu/clutter,heysion/clutter-clone,Distrotech/clutter,heysion/clutter-clone,ebassi/clutter,djdeath/clutter-multithreaded,spatulasnout/clutter,GNOME/clutter,jigpu/clutter,collects/clutter,Distrotech/clutter,djdeath/clutter,djdeath/clutter-multithreaded,Distrotech/clutter,GNOME/clutter,heysion/clutter-clone,collects/clutter,kerrickstaley/clutter-vala,kerrickstaley/clutter-vala,ebassi/clutter,kerrickstaley/clutter-vala,djdeath/clutter,GNOME/clutter,GNOME/clutter,jigpu/clutter,jigpu/clutter,djdeath/clutter-android,djdeath/clutter-android,collects/clutter,heysion/clutter-clone,jigpu/clutter,kerrickstaley/clutter-vala