adding ignores for IntelliJ Idea files/directories

git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@1553116 13f79535-47bb-0310-9956-ffa450edef68
preparation for Ant 1.9.3 release

git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@1553118 13f79535-47bb-0310-9956-ffa450edef68