@paulsamuels => Swift Support

I want to use this in [artsy/eidolon](https://github.com/artsy/eidolon) but I want to keep it as swifty as possible. 

So I've added another flag to add support for outputting as swift and updated the README. You had a lot of training whitespace, so my editor cleaned those up as I was digging around in the source.

When I tried to just run it from master I couldn't get the templates to run, so I made the head / body instance vars because I couldn't figure out how the data gets passed through. Good old ruby.

Looks like this:

``` swift
// Auto generated file from SBConstants - any changes may be lost

enum SegueIdentifier : String {
    case bid = "bid"
}

enum ViewControllerStoryboardIdentifier : String {
    case EnterYourBidDetails = "Enter Your Bid Details"
    case FulfillmentContainerViewController = "FulfillmentContainerViewController"
    case GetYourBidderDetails = "Get Your Bidder Details"
    case PlaceYourBid = "Place Your Bid"
    case SwipeCreditCard = "Swipe Credit Card"
}
```

random side-note, I also spent 2 years in the                      3 years ago :)