C# use YogaSize throughout the measure call chain

Summary:
Java still has the same problem (see #296)

Also there is no need to have double in the method signature as we only use float internally, which could confuse some.
Closes https://github.com/facebook/yoga/pull/300

Reviewed By: splhack

Differential Revision: D4365993

Pulled By: emilsjolander

fbshipit-source-id: 681f8b1725e63eddcfb9a6c756f2ae215a44425a

csharp/Facebook.Yoga/MeasureOutput.cs

@@ -11,24 +11,9 @@ namespace Facebook.Yoga
 {
     public class MeasureOutput
     {
-        public static long Make(double width, double height)
+        public static YogaSize Make(float width, float height)
         {
-            return Make((int) width, (int) height);
-        }
-
-        public static long Make(int width, int height)
-        {
-            return (long)(((ulong) width) << 32 | ((uint) height));
-        }
-
-        public static int GetWidth(long measureOutput)
-        {
-            return (int) (0xFFFFFFFF & (measureOutput >> 32));
-        }
-
-        public static int GetHeight(long measureOutput)
-        {
-            return (int) (0xFFFFFFFF & measureOutput);
+            return new YogaSize { width = width, height = height};
         }
     }
 }