Document the previous fix
Add browse-kill-ring-replace-yank

I'm very used to yank-pop replacing what I just yanked if it wasn't
what I wanted. This brings that behavior to browse-kill-ring.

This might cause puzzling behaviors if you yank something and then
want to yank something else using browse-kill-ring immediately
afterwards. However, it seems that most users of browse-kill-ring
either replace C-y (yank) with browse-kill-ring, or enhance
M-y (yank-pop) without replacing it by using
browse-kill-ring-default-keybindings, so we should be safe to enable
this behavior by default.