Bramble tries to load non-filenames on hover 

Given the following HTML:

``` html
<input name="search" type="image" style="border: 0; margin: 0 0 -9px 5px;" src="search.png" alt="Search" title="Search" />
```

If you hover over `border: 0; margin: 0 0 -9px 5px;` we try to load it:

```
GET border: 0; margin: 0 0 -9px 5px; net::ERR_UNKNOWN_URL_SCHEME
```
