Add support for Visual Leak Detector, since valgrind doesn't support MSVC

Sources/Plasma/CoreLib/HeadSpin.h

@@ -81,6 +81,11 @@ You can contact Cyan Worlds, Inc. by email legal@cyan.com
 #   endif
 #   include <Windows.h>
 
+    // This needs to be after #include <windows.h>, since it also includes windows.h
+#   ifdef USE_VLD
+#       include <vld.h>
+#   endif
+
     // Just some fun typedefs...
     typedef HWND hsWindowHndl;
     typedef HINSTANCE hsWindowInst;

Sources/Plasma/CoreLib/hsThread_Win.cpp

@@ -58,6 +58,11 @@ struct WinThreadParam
 
 static unsigned int __stdcall gEntryPointBT(void* param)
 {
+#ifdef USE_VLD
+    // Needs to be enabled for each thread except the WinMain
+    VLDEnable();
+#endif
+
     WinThreadParam* wtp = (WinThreadParam*)param;
     unsigned int result = wtp->fThread->Run();
     ::ReleaseSemaphore(wtp->fQuitSemaH, 1, nil); // signal that we've quit