WIP (For comments) Transform <newline> in cnxml to html

Transforms:

```
<newline />
<para>hello</para>
<newline count="3" />
<para>lines</para>
<newline count="5" effect="underline" />
```

to:

```
<br/>
<p class="para">hello</p>
<br/><br/><br/>
<p class="para">lines</p>
<hr/><hr/><hr/><hr/><hr/>
```
WIP