Here is a "email_signature" patch, so the signature text can be left out of the language texts in dw.
If you like this patch, pleas use it NOW!
I will not do this work again if the patch is obsolete.
There has to be done a correction in the mail generator code, to insert the $lang['email_signature'].
Texts with the placeholder @DOKUWIKIURL@ inside are intentionally left out of the texts. (Different now then in the Patch_2012-04-27-LanguageTexts, including only the "de en" texts for lang.php)
For the use, don in php code: