bug#1960: 23.0.60; A combination of PC Selection, Visual Lines and emacsclient redefines C-backspace

[Chong Yidong]

Simplified recipe for bug#1960:

1. Put (pc-selection-mode 1) in .emacs
2. emacs --daemon
3. emacsclient -c
4. C-h k C-backspace

<C-backspace> runs the command kill-line, which is an interactive
compiled Lisp function in `simple.el'.

5. C-x C-c
6. emacsclient -c
7. C-h k C-backspace

<C-backspace> runs the command backward-kill-word, which is an
interactive compiled Lisp function in `simple.el'.


PC-selection mode binds [C-delete] to kill-line.  My guess is that some
code for distinguishing delete from DEL isn't run when Emacs is started
as a daemon.  It's only run sometime after the first client frame is
created, which is why C-backspace works properly for the second client
frame.

Could someone take a closer look?