GetFeature(): make sure that the behaviour is not influenced by attribute or spatial filters in the generic implementation (by adding a m_pszAttrQueryString layer member to properly save/restore attribute filter); upgrade OGDI, PG, MySQL, MSSQLSpatial, OCI, SDE, PGeo, ODBC, WALK, IDB, SQLite and Ingres driver to be compliant with expected behaviour; make test_ogrsf test the intended behaviour (#5309)

git-svn-id: https://svn.osgeo.org/gdal/trunk@26688 f0d54148-0727-0410-94bb-9a71ac55c965
Merge branch 'trunk' into trunk_with_coverage