handle object circular reference

Use util.inspect rather than JSON.stringify to short circuit circular references.

lib/le_node.js

@@ -76,10 +76,10 @@ function Logger(ops){
       if(a.length==2 && typeof(a[1])=='object'){
         a[1].level = a[0];
         if(options.timestamp) a[1].time = new Date().toISOString();
-        line+=' '+JSON.stringify(a[1]);
+        line+=' '+util.inspect(a[1]); // handles circular reference better than JSON.stringify
       }else{
         if(options.timestamp) line+=' '+new Date().toISOString();
-        for(var i in a) line+=' '+(typeof(a[i])=='object' ? JSON.stringify(a[i]) : a[i]);
+        for(var i in a) line+=' '+(typeof(a[i])=='object' ? util.inspect(a[i]) : a[i]); // handle circular ref...
       }
       line=line.replace(/\n/g, '\u2028');
       que.push(line+'\n');