[racket] DrRacket editor behaviour change

Robby wrote:

> Just to double check: you mean shift-down, not just down, right?
>
> DrRacket does indeed implement those keystrokes itself, but I'm seeing what
> you describe as the 5.3.1 behavior in 5.3.3 and in the git head under mac
> os x and under a relatively recent git version under linux.
>
> When you choose the Edit | Keybindings | Show Active Keybindings menu item
> and search for home, do you see "select-to-beginning-of-file" as the
> c:s:home key and when you search for "s:down" do you see "select-down" as
> the corresponding keystroke?

No, I think he meant down. I noticed something similar some time after 
upgrading to 5.3.2. I use c:space to "set mark" and c:n to move forward 
a character in Emacs with the intention of later doing a selection 
between mark and point. In 5.3.1, I was able to do this in DrRacket, 
that is, the Emacs cursor commands extended the selection. Now it 
doesn't happen any more. I did look in the keybindings and notice that 
shift seemed to be needed now. Still haven't figured out if I want to 
change the keybindings or change my behaviour. --PR