Email: Mandrill templates and render support.
Merge branch 'feature/mandrill/sendTemplate' of github.com:ignlg/keystone into feature/mandrill/sendTemplate

* 'feature/mandrill/sendTemplate' of github.com:ignlg/keystone:
  Unused var
  Unused var
  Minor comment fix
  Mandrill: send (template), renderMandrill
  sendTemplate support
  sendTemplate support