Fixed #985 : Unittest failed with MinGWx64. And few small improvement were done while looking for mistakes.

Problem was because of Windows uses backslashes '\', not Unix '/'

test/unittest/unittest.h

@@ -78,7 +78,7 @@ inline Ch* StrDup(const Ch* str) {
 }
 
 inline FILE* TempFile(char *filename) {
-#ifdef _MSC_VER
+#if defined(__WIN32__) || defined(_MSC_VER)
     filename = tmpnam(filename);
 
     // For Visual Studio, tmpnam() adds a backslash in front. Remove it.