- started api breaking modification : no more "return CSGObject" but "project.add CSGObject"
* for now very bare bones: all the objects added to the "project" object are "unioned" together , so still one final object on export
* semi hackish implementation, but started modifying the csg.processor (the one in charge of compiling the code in the ui) for a much cleaner
way to do this , and to remove the need for csg globals (ie if this works, no more window.objectRegistry = , no more window.square = etc)
* for now only the project has an "add" method , but this will very likely be moved into the base csg class to be able to build object hiearchies (thus dealing with issue #36)