Allow to select email transport via `MAIL_TRANSPORT` in config
Allow to select email transport via `MAIL_TRANSPORT` in config

Allows to use local sendmail by setting `MAIL_TRANSPORT = 'sendmail'`,
given that the binary is at `/usr/sbin/sendmail` (the default in
Marrow.Mailer 4.0.3).

homeworkprod/byceps,homeworkprod/byceps,homeworkprod/byceps