Removed the spell command. It no longer worked and doesn't really fit
into the "lean mean Zedit".
Removed the shell command. It currently doesn't work and is really not
useful anymore. Made more sense when you wanted to do everything from
Zedit.
Now that the Zshell and Zspell commands are gone, we do not need
out_pipe. Remove out_pipe and supporting code.
Cmd-to-screen was for very old BSD machines that had no fork/exec.
Shell.c was getting very small... merge make.c into it.