Email service implementation
Email service bean instantiation
Logging
Email tests.
Add option to send email in BG
Email sending overrides and tests
Update email service to take file objects instead of strings for template lookup. Better fit for spring inject wiring.
Two reference use cases of email service
Tests for initial emails
Move smtp settings to properties file
Checkstyle fixes
Cleanup
Correct log message
Separate out default "to" address
Merge pull request #180 from SEEG-Oxford/250-email-service

Email service and reference usecases