Move YGLogger into YGConfig and associate YGNodeRef with log events

Summary:
Moves the `YGLogger` into `YGConfig` and pass the `YGNodeRef` into the logger to be able to associate the log messages and assertions with the specific node.

Tackles facebook/yoga#530 and facebook/yoga#446
Closes https://github.com/facebook/yoga/pull/531

Reviewed By: astreet

Differential Revision: D4970149

Pulled By: emilsjolander

fbshipit-source-id: b7fcdaa273143ea2fa35861620b2e4d79f04f0af

csharp/tests/Facebook.Yoga/YogaNodeTest.cs

@@ -248,6 +248,26 @@ namespace Facebook.Yoga
             Assert.AreEqual(0, child2.LayoutY);
         }
 
+        [Test]
+        public void TestPrintOneNode()
+        {
+            YogaNode node = new YogaNode();
+            node.Width = 100;
+            node.Height = 120;
+            node.CalculateLayout();
+            Assert.AreEqual("<div layout=\"width: 100; height: 120; top: 0; left: 0;\" style=\"width: 100px; height: 120px; \" ></div>", node.Print());
+        }
+
+        [Test]
+        public void TestPrintWithLogger()
+        {
+            YogaNode node = new YogaNode(new YogaConfig{Logger = (c, n, l, m) => {}});
+            node.Width = 110;
+            node.Height = 105;
+            node.CalculateLayout();
+            Assert.AreEqual("<div layout=\"width: 110; height: 105; top: 0; left: 0;\" style=\"width: 110px; height: 105px; \" ></div>", node.Print());
+        }
+
         [Test]
         public void TestPrint()
         {
@@ -309,9 +329,10 @@ namespace Facebook.Yoga
             Assert.AreEqual(90.Pt(), node4.MaxHeight);
         }
 
+#if !UNITY_5_4_OR_NEWER
         public static void ForceGC()
         {
-            GC.Collect(GC.MaxGeneration);
+            GC.Collect();
             GC.WaitForPendingFinalizers();
         }
 
@@ -438,6 +459,7 @@ namespace Facebook.Yoga
                 return MeasureOutput.Make(120, 130);
             });
         }
+#endif
 
         [Test]
         public void TestLayoutMargin() {