add csg = cag.rotateExtrude();

add rotateExtrude, using new helper functions _toPlanePolygons, _toWallPolygons,
replace .extrude() with a simplified version using the new helpers.
remove cag.toDebugStr and toDebugStr1

The helpers will also facilitate a sketchup "follow-me" type function (follow a 3d path with a cag)
Merge pull request #49 from bebbi/add_rotateextrude

add csg = cag.rotateExtrude();