Move optional conditions to a suitable place

git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@276929 13f79535-47bb-0310-9956-ffa450edef68

src/main/org/apache/tools/ant/taskdefs/condition/IsPingable.java → src/main/org/apache/tools/ant/taskdefs/optional/condition/IsPingable.java

@@ -15,11 +15,12 @@
  *
  */
 
-package org.apache.tools.ant.taskdefs.condition;
+package org.apache.tools.ant.taskdefs.optional.condition;
 
 import org.apache.tools.ant.ProjectComponent;
 import org.apache.tools.ant.BuildException;
 import org.apache.tools.ant.Project;
+import org.apache.tools.ant.taskdefs.condition.Condition;
 
 import java.net.InetAddress;
 import java.net.UnknownHostException;