cycle: remember cycled window list in server->cycle.views

cycle: remember cycled window list in server->cycle.views

This allows changing the cycled order in the future, e.g. focused order vs
created order.

Functionally, this commit also changes the initially selected window;
before this commit, the previous/next of the topmost window was always
selected, but now the previous/next of the active window is selected first
if it is in the cycled list. This won't change behaviors for most users,
but this ensures that the user can go back to the focused window with
Alt-Tab + Alt-Shift-Tab even when it is not the topmost window.

This commit fixes the TODO in the previous commit by trying to preserve
the selected view when a view is destroyed during window cycling.