[maven-release-plugin] prepare release shindig-project-2.5.1

git-svn-id: https://svn.apache.org/repos/asf/shindig/trunk@1572790 13f79535-47bb-0310-9956-ffa450edef68
[maven-release-plugin] prepare for next development iteration

git-svn-id: https://svn.apache.org/repos/asf/shindig/trunk@1572792 13f79535-47bb-0310-9956-ffa450edef68