Swap last-window & send-prefix bindings

[sorsasampo]

C-a is last-window, a is send-prefix.

This is consistent with screen bindings; C-a C-a toggles to last window,
and C-a a sends the command character.

last-window is usually also needed more often, so it makes sense to make
it more accessible.

Fixes #40.

[bruno-]

Hey, #40 has been open for months but none upvoted or supported the request... so I'm not too eager to merge this.

Couple more arguments to leave as is:

• tmux by default defines <prefix><prefix> (C-b) to send C-b to shell
• tmux book by the pragmatic programmer suggests the same thing
• no existing user-defined bindings are overridden

If this binding turns out to be something the community is divided with, we'll remove from tmux-sensible, not change. We don't want to step on anyone's toes with this plugin. In this case everyone will need to have explicit bindings in their .tmux.confs which you can also do now.

[sorsasampo]

Hey, #40 has been open for months but none upvoted or supported the request... so I'm not too eager to merge this.

After making the PR I noticed #29 from 2015 is basically the same request. But yeah, I can see distinct lack of interest either way.

• tmux by default defines (C-b) to send C-b to shell

That is rather unfortunate, considering the screen default, and general accessibility.

If this binding turns out to be something the community is divided with, we'll remove from tmux-sensible, not change. We don't want to step on anyone's toes with this plugin. In this case everyone will need to have explicit bindings in their .tmux.confs which you can also do now.

That's a sensible approach!

I would love to hear what bindings people use for last-window and send-prefix. I picked mine from somewhere years ago, and they are the other way around.

[dragon788]

Honestly I can't remember how I have it set up in my config, but usually when I hit Ctrl+A I'm either using it as a prefix or wanting to go to the beginning of the line in my shell in emacs mode, tapping A twice while holding Ctrl is much easier in that case than releasing Ctrl and hitting A on its own.

It also keeps the Prefix mapping intact if I connect to a server using screen from within tmux, then I just tap twice versus having to remember/release Ctrl and tap A.

Some of this preference may come from the fact that I rarely use last window and more often search or use the mouse to click a pane or Prefix and Ctrl+h/j/k/l to move between panes.