Fixed bug 2430 - Missing initialization of the variable 'centroid' inside SDL_GestureAddTouch

klose

File: SDL_gesture.c
Method: SDL_GestureAddTouch

When a new SDL_GestureTouch element is added to the global SDL_gestureTouch array the variable 'centroid' of the new element is not initialized.

The problem is that this variable is read isndie SDL_GestureProcessEvent when a SDL_FINGERDOWN event occurs.
CMake: Don't use /NODEFAULTLIB on Windows unless we're Visual Studio.
Added tag release-2.0.2 for changeset be2102f000d0