[emacs] Initial keybindings for windmove

Set the window movement keybindings to C-c <arrow keys>. This should be
changed to something more finger-friendly in the future.
[emacs] Better windmove keybindings

C-c C-b windmove-left
C-c C-f windmove-right
C-c C-n windmove-down
C-c C-b windmove-up

These keybindings have a small overlab with help-forward and help-back,
but that shouldn't cause too many problems.