This code is from Andrew Wiggen (ender79) and reviewed by me. His comments: Implements some tools that were marked TODO: - select nth - separate loose parts And also fixes a few bugs; - extrude and move on normals causes faces to disappear until the move starts - hiding verts/edges/faces does not deselect them - deleting a selection sometimes deletes too much (e.g. a solid cube and a wire cube build of only edges, join them on a single edge, select only the faces of the solid cube and delete, some of the deselected edges from the wire cube were also being deleted)