[maven-release-plugin] prepare release 1.0.0-M20

git-svn-id: https://svn.apache.org/repos/asf/directory/shared/trunk@1513759 13f79535-47bb-0310-9956-ffa450edef68
[maven-release-plugin] prepare for next development iteration

git-svn-id: https://svn.apache.org/repos/asf/directory/shared/trunk@1513761 13f79535-47bb-0310-9956-ffa450edef68