Better support for Docstring in Python

Treats docstring in Python like a regular comment, not as string.

Before:
![Before](https://f.cloud.github.com/assets/33044/1411224/d28804c0-3db3-11e3-95b0-d9f8ca14556c.png)

After:
![After](https://f.cloud.github.com/assets/33044/1411223/d0f57fd4-3db3-11e3-954f-47081fa1dbdb.png)