[RFC] : correct handling of sent mails

[Emmanuel <e allaud wanadoo fr>]

	Hi all,
Here is the solution I come up with to only put sent mails in the Sentbox.
All is in libbalsa/send.c : the send function allways call 
handle_successfull_send to do whatever you need when a message is sent (in 
fact you also have the error handling in there). So it is only there that 
you can copy the mail in the sentbox because there you know it has (not 
has not) been sent. The only thing is that the copy to sentbox is a pref 
so we have to pass it from the GUI back to that send function. But it is 
doable.
So before I mess with the code, any comments ?
Bye
Manu