Generic mails for proposal authors

[ChillarAnand]

We will have list of messages type and templates, say "Request for content", " Talk selected", "Talk rejected", " Schedule published " and message area will populate the data. Reviewer/Admin can edit and send email. We should log the email sent info.

[ananyo2012]

This will be a very helpful feature, since presently we use manual emails for selection/rejection emails.