Move StringToFileConverter back as it references TaskContext

git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@271981 13f79535-47bb-0310-9956-ffa450edef68

proposal/myrmidon/src/java/org/apache/aut/converter/lib/StringToFileConverter.java → proposal/myrmidon/src/java/org/apache/antlib/core/StringToFileConverter.java

@@ -5,7 +5,7 @@
  * version 1.1, a copy of which has been included with this distribution in
  * the LICENSE.txt file.
  */
-package org.apache.aut.converter.lib;
+package org.apache.antlib.core;
 
 import java.io.File;
 import org.apache.aut.converter.AbstractConverter;