Add information for new libyui implementation to libyui-gtk issues

[anaselli]

I understand libyui-gtk is not officially maintained, but can i kindly ask you to open an issue to libyui-gtk? Maybe adding what has been introduced and why, I mean some documentation of the changes.
I have two examples that come into my mind such as activate() pure virtual and now requestMultiPassLayout() and layoutPass().
It isn't clear to me the reason of these addtions, and so it is very hard to implement them in libyui-gtk except trying to copy the Qt and ncurses implementation.
Thanks a lot in advance.