[maven-release-plugin] prepare release specs-2.4.0

git-svn-id: https://svn.apache.org/repos/asf/servicemix/smx4/specs/trunk@1554771 13f79535-47bb-0310-9956-ffa450edef68
[maven-release-plugin] prepare for next development iteration

git-svn-id: https://svn.apache.org/repos/asf/servicemix/smx4/specs/trunk@1554773 13f79535-47bb-0310-9956-ffa450edef68