core(alloc): drop unused code, use memalign() functions instead of hacks

valgrind provides better detection without memory buffer hacks

modules/core/src/system.cpp

@@ -1532,7 +1532,6 @@ BOOL WINAPI DllMain(HINSTANCE, DWORD fdwReason, LPVOID lpReserved)
         {
             // Not allowed to free resources if lpReserved is non-null
             // http://msdn.microsoft.com/en-us/library/windows/desktop/ms682583.aspx
-            cv::deleteThreadAllocData();
             cv::getTlsStorage().releaseThread();
         }
     }