ncurses 6.1 - patch 20190803

+ improve loop limits in _nc_scroll_window() to handle a case where
  the scrolled data is a pad which is taller than the window (patch
  by Rob King).
+ amend the change to screen, because tmux relies upon that entry
  and does not support that feature (Debian #933572) -TD
+ updated ms-terminal entry & notes -TD
+ updated kitty entry & notes -TD
+ updated alacritty+common entry & notes -TD
+ use xterm+sl-twm for consistency -TD