Minor fixups.  Mention that DDB now has a history, and understands emacs-style editing (which it used to have for a long time already). Also mention the `gdb' and `help' commands.  Other commands need an overhaul, too (like the various `show' subcommands), but i don't feel very competent for these.
Minor fixups.  Mention that DDB now has a history, and understands
emacs-style editing (which it used to have for a long time already).
Also mention the `gdb' and `help' commands.  Other commands need an
overhaul, too (like the various `show' subcommands), but i don't feel
very competent for these.

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase