Created Chemistry attribute and Space objects

Added additional chemistry attributes (e.g. 'combustible') and space objects (e.g. 'asteroid').

![screen shot 2014-10-15 at 11 18 11 am](https://cloud.githubusercontent.com/assets/8163408/4650943/cc3a2aa2-5497-11e4-8479-6fecfa6f8565.png)

![screen shot 2014-10-15 at 11 18 35 am](https://cloud.githubusercontent.com/assets/8163408/4650947/cedeaab2-5497-11e4-874c-b9842822b145.png)