[sextante] added "delete R script" action
[sextante] Tests stuff. Added new test models and scripts, geojson testdata and extra tests
[sextante]Saga algorithms can now have harcoded values in description.

Modified SAGA descriptions accordingly and fixed Layer importer to avoid duplicated extensions
[sextante] added some extra space in modeler for inputs tab
[sextante] added Polygonize algorithm by Piotr Pociask
[sextante] modeler tests