[TYPO3-commerce] more usermails

[Firma Cordes]

>additonal you've own marker for new registered user
>
><!--###NEW_USER### begin-->
>Ihre Nutzerdaten fuer den naechsten Besuch:
>Nutzername: ###USERNAME###
>Passwort: ###PASSWORD###
><!--###NEW_USER### end-->
>
>This text is only shown to new user.
>
>Greetings Volker

Dear Volker,
our usermail is really big (we have to include the AGB, because the new law). It´s too much for only one Mail. If there would be an separate mail with the logindatas, there would be an better understanding.

Greetings,
Stephan Cordes