[maven-release-plugin] prepare release uimaj-2.6.0

git-svn-id: https://svn.apache.org/repos/asf/uima/uimaj/trunk@1592861 13f79535-47bb-0310-9956-ffa450edef68
[maven-release-plugin] prepare for next development iteration

git-svn-id: https://svn.apache.org/repos/asf/uima/uimaj/trunk@1592863 13f79535-47bb-0310-9956-ffa450edef68