Remove code related to unsupported versions of actionmailer
Picked and fixed from https://github.com/RailsPlay/mail_safe/commit/dbd7d9be2888ce4b71fc810fba2830db4e9fed2c
Make #developer_email_address return nil if blank
no need to send to the same person a bunch of times in the to address
When mail.send(address_type) doesn't return an array, turn it into one.
Cherry pick some commits pull requested in the original repo
Fix tests
Merge branch 'master' of github.com:watu/mail_safe