Change Register function to use stdcall

Older versions used stdcall, so change the signature for backwards compatibility.
diff --git a/src/Main/Register.cpp b/src/Main/Register.cpp
index 4372f99..5fd54ba 100644
--- a/src/Main/Register.cpp
+++ b/src/Main/Register.cpp
@@ -57,7 +57,7 @@
 
 extern "C"
 {
-	void Register(char *licenseKey)
+	void REGISTERAPI Register(char *licenseKey)
 	{
 		InitValidationApp();
 		memset(validationKey, '\0', sizeof(validationKey));
diff --git a/src/Main/Register.hpp b/src/Main/Register.hpp
index 712a84c..16b2dc0 100644
--- a/src/Main/Register.hpp
+++ b/src/Main/Register.hpp
@@ -29,7 +29,12 @@
 

 extern "C"

 {

-	void Register(char *licenseKey);

+#ifdef _WIN32

+#define REGISTERAPI __stdcall

+#else

+#define REGISTERAPI

+#endif

+	void REGISTERAPI Register(char *licenseKey);

 }

 

 #endif   // Register_hpp