Win: Code cleanup, create internal helper functions _dw_window_get_cinfo() and _dw_window_new_cinfo() to simply code dealing with ColorInfo structs. Remove the vcenter and unused user fields replacing them with style and rect. Style will cache the requested style for a window instead of the active style, which may differ based on the state of the system. So now we can just check the style to see if VCENTER is set.