[RP] tab completion/editing keys patch

[Rupert]

There's a patch against current cvs here:

 http://rupert.dyndns.org/rp-inputbar.diff

that does this:

 - tab completion for rp commands and better editing in input bar

 - fixes some potential overflows in marked_wrapped_message

 - adds a new (and pretty useless) help variant, 'listcmds'

 - contains a bodge to let you use caps_lock as your command key

Check it out and let me know what you think...

Rupert