fix memory leak problem when streaming huge files (#154)

PR reverts commits [2e4fcb](2e4fcb2) and [8c1206](8c1206e) that introduced memory leaks.

Please squash merge.

resolves #153

Author: daern91

bin.js

@@ -115,6 +115,7 @@ exports.parse = function (path, map) {
 
         stream.queue(data)
       }
+    if (this.value) delete this.value[this.key]
     for(var k in this.stack)
       if (!Object.isFrozen(this.stack[k]))
         this.stack[k].value = null

index.js

@@ -12,4 +12,4 @@
     {"blbl": [{}, {"a":0, "b":1, "value":"3"}, 10]},
     {"value": 4}
   ]
-}
+}