tty-defined-color-alist needs to be terminal local

[Dan Nicolaescu]

I just saw this note in README.multi-tty:
** See if `tty-defined-color-alist' needs to be terminal-local.

It does need to be terminal local.

{xterm,rxvt}-register-default-colors call tty-color-define which changes
tty-defined-color-alist.

To see the effect of this, do on an xterm
env TERM=xterm-256color emacsclient -t
M-x list-colors-display RET
and then in an rxvt
env TERM=rxvt=88color emacsclient -t

and see how the colors in the xterm-256color frame change...