Update supervisedclassification.py
Update supervisedclassification.py
Update ImportIntoPostGIS.py
Update GrassAlgorithm.py
fix data retrieval in attribute table from geometryless spatialite tables
Merge pull request #915 from gioman/master

Makes SAGA supervised classification work also with SAGA 2.0.8, fixes #8715. Add schema selection to GUI of "Import into PostGIS" tool (fixes #8513). Fixes export of GRASS vectors (fix #8515)
[processing] handle non-ASCII characters in layer name when exporting (fix #8673)
[processing] add gdal2xyz tool (fix #8723)