vsgDynamicWindows broken on Windows

[AnyOldName3]

As we've discussed in the context of the Win32 window resizing problem, the message pump (implemented in vsg::Win32_Window::pollEvents) needs to be called on the same thread as owns a window to affect that window. The child windows in the vsgDynamicWindows example are created in loader threads, and those threads don't run message pumps, so messages never reach those windows, and they freeze (both literally and in the didn't handle any window messages for five seconds Win32 definition).

[AnyOldName3]

Also, it emits

Warning: Error code: 1400 | Win32_Window::~Win32_Window() ::DestroyWindow(_window) failed : Invalid window handle.

twice on exit as DestroyWindow can only be called from the thread that created the window.

[AnyOldName3]

Another post I thought I'd posted immediately after the last one, but still seems to be unposted now I'm looking at this tab today:

Also, it emits

Warning: Error code: 1400 | Win32_Window::~Win32_Window() ::DestroyWindow(_window) failed : Invalid window handle.

twice on exit as DestroyWindow can only be called from the thread that created the window.