target/site fixes

1. When running `mvn site` target/site/index.html has an empty navcolumn:
```html
<div id="leftColumn">
  <div id="navcolumn">
    <a href="http://maven.apache.org/" title="Built by Maven" class="poweredBy">
      <img class="poweredBy" alt="Built by Maven" src="./images/logos/maven-feather.png" />
    </a>
  </div>
</div>
```
Deleting site.xml fixes the problem.

2. The binary image files were being filtered making them unreadable when running `mvn test`