bug#5331: Term mode doesn't set tty erase

[Scott Bell]

Under Mac OS X 10.6.2, Emacs 23.1.90.1, in an M-x term buffer
running /bin/bash, `stty -a' reports the following:

speed 9600 baud; 33 rows; 90 columns;
lflags: icanon isig iexten echo echoe -echok echoke -echonl echoctl
        -echoprt -altwerase -noflsh -tostop -flusho pendin -nokerninfo
        -extproc
iflags: -istrip icrnl -inlcr -igncr ixon -ixoff ixany imaxbel -iutf8
        -ignbrk brkint -inpck -ignpar -parmrk
oflags: opost onlcr -oxtabs -onocr -onlret
cflags: cread cs8 -parenb -parodd hupcl -clocal -cstopb -crtscts -dsrflow
        -dtrflow -mdmbuf
cchars: discard = ^O; dsusp = ^Y; eof = ^D; eol = <undef>;
        eol2 = <undef>; erase = <undef>; intr = ^C; kill = <undef>;
        lnext = ^V; min = 1; quit = ^\; reprint = ^R; start = ^Q;
        status = ^T; stop = ^S; susp = ^Z; time = 0; werase = ^W;

It seems like the least surprising thing would be to define
erase to ^? so that most programs will behave as expected 
when the DEL key is typed.