Implement constructor overloading

Added "Hyperloop.ctor" to suport basic overloading for iOS constructors.

```javascript
var window = Hyperloop.ctor(UIWindow, 'initWithFrame:').call(bounds);
var view = Hyperloop.ctor(UIView, 'initWithFrame:').call(frame);
```

goes to

```objectivec
UIWindow * instance = [[[UIWindow alloc] initWithFrame:static_cast<CGRect>(bounds)] autorelease];
UIView * instance = [[[UIView alloc] initWithFrame:static_cast<CGRect>(frame)] autorelease];
```

You can still use "new" to call default constructor like this:

```
var window = new UIWindow();
```

goes to

```
UIWindow * instance = [[UIWindow new] autorelease];
```