Fix invalid highlighting block comment(#205)

### Original

![original](https://f.cloud.github.com/assets/554281/1865198/8449ef28-7808-11e3-8e6d-585ffe16ad97.png)

### Fixed version

![fixed](https://f.cloud.github.com/assets/554281/1865200/8855fe4a-7808-11e3-9da4-f1ce0170ed05.png)


Cc: @thieman