fix(chunkstream): max call stack thrown when parsing large pngs

lib/chunkstream.js

@@ -48,6 +48,7 @@ ChunkStream.prototype.read = function(length, callback) {
         func: callback
     });
 
+    process.nextTick(function() {
       this._process();
 
       // its paused and there is not enought data then ask for more
@@ -56,6 +57,7 @@ ChunkStream.prototype.read = function(length, callback) {
 
           this.emit('drain');
       }
+    }.bind(this));
 };
 
 ChunkStream.prototype.write = function(data, encoding) {