Added SelfClosingTag mode to support inline tags 

Hey Wes,

This should fix the underlying problem with in-line tags within the parser.

For example the following html snippets when parsed will result in no changes:
```html
<strong>hello<hr /></strong>
<em>hello<br />world</em>
```

In a nutshell I added a new regular expression to check for inline-tags and then have a new handler in the parser which just treats it like an open tag, but without having the mode state set to `OpenTag`.

Craig