Set initial state's title to document.title

I had a bug where the document title would become set to '', when I changed `document.location.hash`.

I realized this was because History.js noticed the hash change, and tried to set the title to my initial state's title:

``` javascript
			if ( !title ) {
				firstState = History.getStateByIndex(0);
				if ( firstState && firstState.url === newState.url ) {
					title = firstState.title||History.options.initialTitle;
				}
			}
```

But my initialState didn't have a title, because extractState couldn't read the title of the page, so I added that feature.

I feel like I might be missing something here.