Updated BrowserController so can now render in landscape

Hi, I've just made a very small change so when the BrowserController is displayed on iPhone, it can now also be rendered in landscape.  

I also tried to get the rest of the app to support landscape and it all seems to work, except when rendering the SubmissionTableCell (the text would stretch / compress when switching between landscape and portrait), so I've left it for now and just made the BrowserController support landscape.