Parses only ! already

I'm currently running 0.7.0-dev and following happens:

if my content is:

```
!Spoiler
```

it gets rendered as:

``` html
<blockquote class="spoiler">
    <p>Spoiler</p>
</blockquote>
<blockquote>
</blockquote>
```

So as you can see, it already replaces the text with spoiler even though it doesnt start with `>!` and it adds an empty blockquote after it
