Sending email when new participant is created.

The email is sent as no-reply to the admins. We need to make sure that the ADMINS field in the settings is populated, otherwise no mail will be sent.
The email points out directly which admin link to foloow to approve the participant.
Merge pull request #135 from e-Luminate/134-email-admins-new-participant

134 email admins new participant. Fix 134