Merge pull request #38 from MichiBe/develop

final pull request bevor release 0.3
fixed readme
added scm tag
added mailing list
added property for latest version (improved site generation)
added distribution management
cleanup
preparing for release
fixed image links
added gpg key
added more plugins
updated license plugin
added license headers
fixing test
removed empty dir
fixed url
downgraded jgitflow-plugin
added sign artifacts profile
added project url
updating poms for 0.3 release