wishlist: git send-email improvement

Hi,

Here's a little wishlist for send-email

- Use From: field extracted from patch:
  If there's no configuration for user.email and From: field is 
  different than default auto generated From: address, 
  git send-email should use the one in the patch as default.

- Use To: field extracted from patch
  I've setup format-patch to add a default To: field with
  format.headers="To: xxx@yyy". But git send-email did not use it and 
  ask for a To: value.
  If there's no --to or sendmail.to, send-email should use To: value 
  extracted from patch and ask for user confirmation.

I've tried to add the later to git-send-email, but failed to fix it by
now in a reasonable time amount.

Regards.

-- 
Yann Droneaud