Avoid duplication between copy ctor and assignment operator. Also extract the assignment of everything not including the event type in a reusable function as this can be useful for key event generation code in wxGTK and possibly other ports. git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@69890 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775