Update supervisedclassification.py
Update supervisedclassification.py
Update ImportIntoPostGIS.py
Update GrassAlgorithm.py
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)