* usr/share/byobu/keybindings/common, usr/share/byobu/keybindings/f-
  keys.screen, usr/share/byobu/keybindings/f-keys.screen.disable,
  usr/share/byobu/keybindings/f-keys.tmux,
  usr/share/byobu/keybindings/f-keys.tmux.disable,
  usr/share/doc/byobu/help.tmux.txt: LP: #945069
  - unbind ctrl-left/right/up/down in byobu
    + previously was used to resize splits
    + some users unfortunately expect ctrl-left/right to move the
      cursor around words
  - resizing splits is something that happens relatively infrequently,
    so bind these to shift-alt-up/down/left/right
  - use alt-left/right to move between windows
  - use alt-up/down to move between sessions
  - source the disable bindings just before sourcing the byobu bindings,
    this enables a clean undo of bindings
  - document the changes in the help text