mail/mailslurper: New port

MailSlurper is a small SMTP mail server that slurps mail into oblivion!

MailSlurper is perfect for individual developers or small teams writing
mail-enabled applications that wish to test email functionality without
the risk or hassle of installing and configuring a full blown email
server.

It's simple to use! Simply setup MailSlurper, configure your code and/or
application server to send mail through the address where MailSlurper is
running, and start sending emails!

MailSlurper will capture those emails into a database for you to view at
your leisure.

PR: 268242
Reported by: einar@isnic.is
Tested by: bofh
Approved by: einar@isnic.is (submitter is maintainer)