Fixed bubble keys (moving lines up and down)

I couldn't get <C-Up> to register most of the time. I suspect its
a terminal/tmux thing.  Plus, I now loathe the arrow keys.

The default `]e` and `[e` isn't natural to me yet, so I still needed
another shortcut.

So I chose `<C-S-J>` and `<C-S-K>`.
Added tmux pane navigation support.

This adds the short cuts for moving around panes in vim by
pressing control-[hjkl]

However, with the proper tmux.conf settings (see the comments)
and running under tmux, you can use the same keys to cross from
tmux panes into vim windows and back!

Very clever.