"clean" target in generated build.xml files fails with empty target directory

The Tuscany maven-ant-generator plugin generates "clean" targets of the form:

<target name="clean">
<delete includeemptydirs="true">
<fileset dir="target"/>
</delete>
</target>

This fails if the "target" directory doesn't exist. The generated code should be changed to:

<target name="clean">
<delete dir="target" includeemptydirs="true"/>
</target>

which works in all cases.