Email Sending Module

[icydee]

We need a new module which can deal with sending Emails to users. This should be in the KA::Email namespace.

The module should provide the following capabilities.

• Use a template system to create emails (check with TheTower, I think he has some ideas on this)
• In development mode it should prevent emails going out to real users, but should output either to a configured developers email address, or to a file.
• See if we can/need a separate docker container to mange an email service or whether the current KA-Server container can do it directly.
• Some of the functionality can be taken from the existing code which uses the Email::Stuff module but it would be nice to factor out the functionality into it's own module.