Attempt to aggregate checkstyle reports.
Attempt to aggregate checkstyle reports.

The aggregate report checkstyle-aggregate.html is properly created
in the site at top level but there are two problems:

 - it does not appear automatically in the Reports menu
   (this could easily be fixed in the site.xml file)
 - it is not themed at all and is a simple ugly html page
sdinot/hipparchus,Hipparchus-Math/hipparchus,Hipparchus-Math/hipparchus,sdinot/hipparchus,Hipparchus-Math/hipparchus,Hipparchus-Math/hipparchus,sdinot/hipparchus,sdinot/hipparchus