Doesn't run on Windows 10 Creators Update (when compiling to 32 bit)
Trying to run first example from NiGui with i686 MinGW (compiled .exe is 32bit):
```cmd
E:\Projects\NiGui>example_01_basic_app.exe
could not import: SetWindowLongPtrW
```
With x32 Visual Studio compiler it's the same.

While compiling for amd64 (with x64 bit mingw or cl.exe), everything works perfectly

Probably NiGui must do checking for i386 or amd64 in winapi bindings, like this - https://github.com/jangko/nimCEF/blob/0946c0b39b1cc4976923a8af4dfc779bb9f6b70b/platform/winapi.nim#L1103

Also:
https://stackoverflow.com/questions/24664245/attributeerror-function-getwindowlongptrw-not-found
https://groups.google.com/forum/#!topic/golang-nuts/pkmwc8k0DpU
