saga_api, csg_table: enable index creation on point clouds
saga_gui, point cloud: enable display of attributes table
saga_api, clipper: update to official 6.0.0 release
io_shapes, export to xyz: should fix bug #170 'Export Shapes to XYZ exports only the first character of strings' http://sourceforge.net/p/saga-gis/bugs/170/
polygon dissolve: supporting statistics for merged polygons
saga_gui, table view: bug fix and improved performance (testing needed)
saga_gui: enable 'unique values' and 'quantiles' methods in 'Create Lookup Table' for point clouds
Updates for AUTHORS and README files
Export Shapes to XYZ: do not use Stream.Write because of unicode incompatibility, completes r1869
Convert Points to Line(s): optionally output additional attribute with point order per line (this allows to convert the points back to lines later)