AddThumbBarButton should return bool value.
Coding style problem fix.

- Use wxVector instead of old WX_XXX_LIST() macros.
- Prefer wxDECLARE_NO_COPY_CLASS() to DECLARE_NO_COPY_CLASS().
- Fix naming nits for wxTaskbarButtonState enum elements.
- Use wxCHECK_MSG() instead of silently return in the SetProgressValue.
- Forward-declare ITaskBarList3 in current lib.