title: set a new password to a user in Meteor
body: <p>here's what i'm trying to do , 
  when the user links a social account , the user is then created , but i wish to have the user submit a password , to allow him to log without his email and password .</p>
  
  <p>i created a form to allow the user to submit his password , but i couldn't find the right method to use , the only one available is </p>
  
  <pre><code>Accounts.changePassword(currentPassword, newPassword, function(error) {
          if (error) {
              message = 'There was an issue: ' + error.reason;
          } else {
              message = 'You reset your password!'
          }
      });
  </code></pre>
  
  <p>the problem with this method is that i don't know the current password of the user , he doesn't have a password yet but still the user does exist , when i call Meteor.user().</p>
  
  <p>any suggestion ?</p>