Change version numbers to 1.2.5.2 and release dates

Also added "-motley" to ZLIB_VERSION in zlib.h, so that versions
in-between 1.2.5.1 and 1.2.5.2 that are pulled down from github
can be identified as such if bugs are reported on them.

contrib/dotzlib/DotZLib/UnitTests.cs

@@ -156,7 +156,7 @@ namespace DotZLibTests
         public void Info_Version()
         {
             Info info = new Info();
-            Assert.AreEqual("1.2.5.1", Info.Version);
+            Assert.AreEqual("1.2.5.2", Info.Version);
             Assert.AreEqual(32, info.SizeOfUInt);
             Assert.AreEqual(32, info.SizeOfULong);
             Assert.AreEqual(32, info.SizeOfPointer);