WL#3005: Editing stored procedures in $EDITOR

I was in class with Harrison and getting frustrated that I editing stored
procedures in the command line client was so clunky. I was wondering why
something like \e wouldn't work to pop the stored procedure text into the
$EDITOR, and Harrison suggested I just write it. So I took a stab at it and have
something that's mostly workable for me. I think it could still be better, but I
imagine I should start getting some input before I go TOO far. 

I've attached a patch that implements this:

- Adds a command, editproc with a shortcut \E that operates like: 
    \E procname
- If the proc exists: 
  pulls the text of the proc into the $EDITOR using the same rules as \e
- If it doesn't exist:  
  puts template text into the $EDITOR 

- When the editor is exited, editproc runs a drop proc and then the new proc code. 
- If there is an error in the new proc creation, the old proc is re-run back in

The big remaining question mark for me is what to do with invalid code that the
user edits? One wouldn't want to lose changes just for a syntax error - or that
could just be a caveat of the feature. 

Anyway, it works for me at the moment - although I haven't gone through the code
style guidelines because I haven't had intranet access since I started working
on this. (That's fixed now)