Add ability to specify dimensions of browser window

[MikeMugu]

User Story

As a user, I want the ability to specify what size to put the browser in when running tests.

Acceptance Criteria

1. I should be able to specify the browser size in pixel dimensions when running tests.
2. When tests run, the browser should adjust to the size I specify before the test executes.

[jimthemighty]

I've been using a step called:
When I change my Viewport to "" and ""

And then the Step Definition is
[StepDefinition(@"I change my Viewport to (.) and (.)")]
public void WhenIChangeMyViewportToAnd(int p0, int p1)
{
Browser.ResizeTo(p0, p1);
}

I'll try to add an example of this.