Allow test suites to be run on Windows

For a start, they don't even compile with Visual Studio due to strcasecmp
being missing.  Secondly, on Windows Perl scripts aren't executable and have
to be run using the Perl interpreter directly; thankfully CMake is able to
find cygwin Perl straight away without problems.
diff --git a/tests/suites/helpers.function b/tests/suites/helpers.function
index 8f681db..6af918c 100644
--- a/tests/suites/helpers.function
+++ b/tests/suites/helpers.function
@@ -15,6 +15,8 @@
 #ifdef _MSC_VER
 #include <basetsd.h>
 typedef UINT32 uint32_t;
+#define strncasecmp _strnicmp
+#define strcasecmp _stricmp
 #else
 #include <stdint.h>
 #endif