[maven-release-plugin] prepare for next development iteration
Merge branch 'release/0.2.1' into develop
QP Bugfix, small additions and Cleanup

* quoted-printable transfer encoding was forced on the main part, which caused problems with some Exchange Servers. Now reverting to standard JavaMail behaviour and using Springs MimeMessageHelper

* added the ability to add attachments

* added the ability to set an SMTP envelope from

* housekeeping
Refactoring and documentation

* Replaced EmailException with Springs default MailException
* some refactoring
* documentation added
[maven-release-plugin] prepare release v0.2.2
Merge branch 'release/0.2.2'