Add INIT_WITH_EPSG=no option when opening spatialite db.

When using spatialite 4 OGR needs several minutes to initialize the database
without this option. It seems this is fixed in trunk OGR, but we don't want
to wait for that. The INIT_WITH_EPSG=no seems to help and also makes the
database smaller. I can't see any drawbacks...
Use exec in runtest.sh
Make sure there are warnings created for invalid polygons when splitting