preliminary support for Kakadu V7.x

git-svn-id: https://svn.osgeo.org/gdal/trunk/gdal@25950 f0d54148-0727-0410-94bb-9a71ac55c965
make sure we refresh kdu_cache.cpp after a clean

git-svn-id: https://svn.osgeo.org/gdal/trunk/gdal@25951 f0d54148-0727-0410-94bb-9a71ac55c965