do not try to recurse into gl-vis object in Lib.minExtend

- this led to max call stack errors previously
  on snapshots

Author: etpinard

src/lib/index.js

@@ -384,7 +384,7 @@ lib.minExtend = function(obj1, obj2) {
     for(i = 0; i < keys.length; i++) {
         k = keys[i];
         v = obj1[k];
-        if(k.charAt(0) === '_' || typeof v === 'function') continue;
+        if(k.charAt(0) === '_' || typeof v === 'function' || k === 'glTrace') continue;
         else if(k === 'module') objOut[k] = v;
         else if(Array.isArray(v)) objOut[k] = v.slice(0, arrayLen);
         else if(v && (typeof v === 'object')) objOut[k] = lib.minExtend(obj1[k], obj2[k]);