creating temporary directory with a unique name

git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@1584506 13f79535-47bb-0310-9956-ffa450edef68
creating temporary directory with a unique name

git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@1585230 13f79535-47bb-0310-9956-ffa450edef68
Upstream merge
Convert remaining BuildFileTests to use BuildFileRule