Maximise canvas with a set constraint in setup

I wanted a banner type game that could be hosted on a footer of a web page. 
http://ss14-team-61.divshot.io/

```
.setup({ maximize: true })
```
Allowed me to stretch the canvas to the maximum, but I needed a fixed height.
The attached code will give you the ability to set constraints and still have a maximum.
```
.setup({ maximize: true, height: 200 })
```

As your webpage gets longer, the scrollbar appears and sets the alignment of the canvas off.
This will decrease the width of the canvas by 17px.
```
.setup({ maximize: true, height: 200, pagescroll: true })
```