Read the allocated port from the ServerSocket

ServerSocket has support to search for any free
port if you pass '0' as port number. In this case
the port in the ServerSetup does not match the
actually aquired port.
Merge pull request #29 from signed/respond-with-actually-allocated-port

Read the allocated port from the ServerSocket
Updated documentation/site for Release 1.4.0
Fix for JaCoCo and Surefire / argLine
Sonar fixes
Fixed wrong fetch of server address: use socket address
More sonar violation and generic warnings fixes
Fixed bug in #28. Modified MailCommand class to avoid populating the sender field if it's empty per RFC5321 specifications.
Added a unit test class SMTPCommandTest to test socket level commands to GreenMail SMTP server.
Merge pull request #31 from buildscientist/issue-28

Fixed bug in #28. Modified MailCommand class to avoid populating the sen...