[maven-release-plugin] prepare release log4j-2.0-beta9

git-svn-id: https://svn.apache.org/repos/asf/logging/log4j/log4j2/trunk@1523249 13f79535-47bb-0310-9956-ffa450edef68
[maven-release-plugin] prepare for next development iteration

git-svn-id: https://svn.apache.org/repos/asf/logging/log4j/log4j2/trunk@1523251 13f79535-47bb-0310-9956-ffa450edef68