Fix highlighting regexp literal

Original code highlights regexp wrong if another '/' is existed in same line,
such as:

```coffee
   emit = emit.replace /hubot/ig, "<b>#{robot.name}</b>"
```

Original code treats `/hubot/ig, "<b>#{robot.name}</` as regexp literal.
Because it uses greedy matching.

### Original code highlighting
![orig-regexp-literal](https://f.cloud.github.com/assets/554281/1693328/f57d3aa0-5e8c-11e3-9c80-aa5ee78326fa.png)


### Fixed version highlighting

![fixed-regexp-literal](https://f.cloud.github.com/assets/554281/1693330/045e151c-5e8d-11e3-8460-2575e1b31721.png)

Please see this patch.