fixed handling of '*' followed immediately by a blank line

I was confused at first when I tried out doctrine because it failed to parse something like this:

```javascript
/**
 * Description
 *
 * @param {type} name blah blah blah
 */
```

After some trial and error I discovered it was because of that middle `*` character, followed immediately by a newline character. I fixed the issue by adding a space after the `*`.

This change fixes `unwrapComment` so that `*` characters do NOT have to be followed by a space in order to be ignored.