Make validate_email accessible to others "as is"

One can use:
from Products.NaayaCore.EmailTool.EmailValidator import validate_email
validate_email("email")
to check an address syntax

Fix test

git-svn-id: https://svn.eionet.europa.eu/repositories/Naaya/trunk/eggs/Naaya@20560 a0171fae-0946-0410-966d-b1775066cd26