Fix TIL driver using overview (#3482)
Now TIL can use tile's overviews and it's own overviews (last have priority)
Add set projection and geotransformation for TILDataset

git-svn-id: https://svn.osgeo.org/gdal/trunk@25588 f0d54148-0727-0410-94bb-9a71ac55c965