check cc list

if cc list is not empty and fail_silently is not set, raise an
exception!
support for attachments

added support for attachments of both types, tuple as well as MIMEBase
as per
https://docs.djangoproject.com/en/dev/topics/email/#django.core.mail.Ema
ilMessage
Merge pull request #1 from mehernosh/master

attachment support + cc list check