[maven-release-plugin] prepare release 1.5.0-RC2

git-svn-id: https://svn.apache.org/repos/asf/accumulo/branches/1.5@1480505 13f79535-47bb-0310-9956-ffa450edef68
[maven-release-plugin] prepare for next development iteration

git-svn-id: https://svn.apache.org/repos/asf/accumulo/branches/1.5@1480507 13f79535-47bb-0310-9956-ffa450edef68