allow comments in import statement

fixes #21 

Before
![before](https://cloud.githubusercontent.com/assets/2543659/5289540/e71ccfc8-7b3e-11e4-895f-0b322e763738.png)

After
![after](https://cloud.githubusercontent.com/assets/2543659/5289541/e71dfba0-7b3e-11e4-947d-f6201894429d.png)