if -u USER supplied is different to user in rcfile, then we should ask for the password?

Allow admin commands to be used with dial. (readline?)

If you do "dial &" and then enter "fg" to enter the password, we will not be
able to proceed. (Nor even exit from the terminal).

In Links' OS Shell, if you use "connect.sh", you can't return to Links until
that connect.sh session is closed. This is because Links (at least as of 0.92)
waits until all launched processes have exited before allowing you to return.

With connect.sh run, we always exit with 1 due to "exec dial, kill dial"
