Fix warnings

Author: PierrePerrin

ShadowView/ShadowView/UIImageEffects.swift

@@ -152,11 +152,11 @@ public extension UIImage {
  return nil
  }
  if maskImage != nil && maskImage!.cgImage == nil {
- print("*** error: maskImage must be backed by a CGImage: \(maskImage)")
+ print("*** error: maskImage must be backed by a CGImage: \(String(describing: maskImage))")
  return nil
  }
 
- let __FLT_EPSILON__ = CGFloat(FLT_EPSILON)
+ let __FLT_EPSILON__ = CGFloat(Float.ulpOfOne)
  let screenScale = UIScreen.main.scale
  let imageRect = CGRect(origin: CGPoint.zero, size: size)
  var effectImage = self
@@ -205,7 +205,7 @@ public extension UIImage {
  //
 
  let inputRadius = blurRadius * screenScale
- let d = floor(inputRadius * 3.0 * CGFloat(sqrt(2 * M_PI) / 4 + 0.5))
+ let d = floor(inputRadius * 3.0 * CGFloat(sqrt(2 * .pi) / 4 + 0.5))
  var radius = UInt32(d)
  if radius % 2 != 1 {
  radius += 1 // force radius to be odd so that the three box-blur methodology works.