Added options to like/nlike operator to allow for regex flags

Not sure if there's a cleaner way to do this. Basically just added the ability to specify Regex flags so that case insensitive search can be done.

Format would be:
```
Post.find({
  where: {
    title: {
      like: 'someth.*',
      options: 'i'
    }
  }
});
```