Should we drop the nested *ref elements?

[Stefan Bodewig]

If we add refid attributes to FileSet and PatternSet as well, these
could be superfluos, for example

     <chmod perm="+x">
       <fileset dir="${bin.dir}">
         <patternsetref refid="chmod.patterns"/>
       </fileset>
     </chmod>

could as well be written as

     <chmod perm="+x">
       <fileset dir="${bin.dir}">
         <patternset refid="chmod.patterns"/>
       </fileset>
     </chmod>

This might even be easier to read.

Some tasks would need to be changed but given that these things are
quite new I don't fear to break anything. Comments?

Stefan