set of quick hacks and serious changes to get tube twist under control

modules/geom/src/quat.cc

modules/geom/src/quat.hh

modules/gfx/src/gfx_object.cc

modules/gfx/src/impl/backbone_trace.cc

modules/gfx/src/impl/cartoon_renderer.cc

modules/gfx/src/impl/entity_detail.cc

modules/gfx/src/impl/entity_detail.hh

modules/gfx/src/impl/sline_renderer.cc

modules/img/alg/pymod/export_transcendentals.cc

modules/img/base/src/vecmat.hh