Add wrapContent() methods

[lucdion]

Add wrapContent() methods that adjust view's width & height to wrap all its subviews

The following methods are useful to adjust view's width and/or height to wrap all its subviews. These methods also adjust subviews position to create a tight wrap.

Methods:

• wrapContent()
wrapContent(padding: CGFloat)
wrapContent(padding: UIEdgeInsets)
  Adjust the view's width and height to wrap all its subviews. The method also adjusts subviews position to create a tight wrap. It is also possible to specify an optional padding around all subviews.
• wrapContent(:WrapType)
wrapContent(:WrapType, padding: CGFloat)
wrapContent(:WrapType, padding: UIEdgeInsets)
  Adjust the view's width AND/OR height to wrap all its subviews. WrapType values are .horizontally/.vertically/.all It is also possible to specify an optional padding around all subviews.

Usage examples:

	view.pin.wrapContent().center()   // wrap all subviews and centered the view inside its parent.
	view.pin.wrapContent(padding: 20) // wrap all subviews with a padding of 20 pixels all around
	view.pin.wrapContent(.horizontally)

[antoinelamy]

Why not using CGRect.union() to find the bounding rect instead of computing each rect component individually? All this loop and the local min/max variables could probably be replaced by the statement let boundingRect = subviews.reduce(CGRect.zero, { $0.union($1.frame) }). The min/max values are all available on a CGRect directly.

[lucdion]

Nice idea, I'll do that 👍

[antoinelamy]

Appart from the Android inspired name, 👍 😉