Bug reported by Guillaume LeCocq

Setting both 'xray' and 'transp' did not work proper. Had to add one
extra check, and switch drawing order. Now a transparent object gets
drawn OK as Xray too. :)

source/blender/src/drawobject.c

@@ -3480,7 +3480,7 @@ void draw_object(Base *base)
 
 	/* xray delay? */
 	if(!(G.f & G_PICKSEL)) {
-		if(!G.vd->xray && (ob->dtx & OB_DRAWXRAY)) {
+		if(!G.vd->xray && !G.vd->transp && (ob->dtx & OB_DRAWXRAY)) {
 			add_view3d_after(G.vd, base, V3D_XRAY);
 			return;
 		}