edebug-set-initial-mode: C-x C-a C-m binding.

[Alan Mackenzie]

Hello, Emacs.

I've just committed a change to master which resurrects
`edebug-initial-mode-alist' and `edebug-set-initial-mode', which were
commented out in archaeological times.  The command allows one to set
`edebug-inital-mode' interactively with C-x C-a C-m.

The binding C-x C-a C-m really belongs to GUD, but isn't used there, so
I purloined it.  If there are any objections, please say so, giving an
alternative suggestion.

-- 
Alan Mackenzie (Nuremberg, Germany).