a possible fix of #238

1) I stopped the stdio watcher completely since it puts the output in wrong locations.

2) I fixed the reading of read_stdout pipe.

Note: There is one drawback of this fix. If the call runs very long, we won't be able to see partial stdout. The stdout will be flushed when the call finishes.

![screen shot 2014-10-17 at 2 57 44 am](https://cloud.githubusercontent.com/assets/1690993/4677185/1124be46-55e4-11e4-85c4-80ff95b685bb.png)