make wireframe a global toggle

src/mesh/api.js

@@ -157,13 +157,6 @@ let selection = {
         return selection;
     },
 
-    wireframe() {
-        for (let m of selection.models()) {
-            m.wireframe(...arguments);
-        }
-        return selection;
-    },
-
     boundsBox() {
         for (let m of selection.groups()) {
             m.showBounds(...arguments);
@@ -240,6 +233,12 @@ let api = mesh.api = {
         ));
     },
 
+    wireframe() {
+        for (let m of api.model.list()) {
+            m.wireframe(...arguments);
+        }
+    },
+
     selection,
 
     group,