Patch fixes from regression testing in 5.2.

Unit Tests fixed to 5.3 plus due to dependancy on Unity Test Tools (which also have issues in 5.2 :D)

--HG--
branch : develop_5.3

Scripts/Editor/CompressionTests.cs

@@ -1,4 +1,5 @@
-using NUnit.Framework;
+#if UNITY_5_3_OR_NEWER
+using NUnit.Framework;
 using System;
 using System.IO;
 using System.Linq;
@@ -215,3 +216,4 @@ public class CompressionTests  {
 
     }
 }
+#endif