Merge pull request #1679 from ramox81/codex/surface-associativity-sources

Associative extruded, revolved and lofted surfaces; spline and ellipse sources

# Conflicts:
#	src/app/command_driver/solid3d.rs
#	src/scene/dwg_native_constraints.rs
#	src/scene/model/mod.rs
#	src/scene/model/sweep_command_model.rs
#	src/scene/model/sweep_model.rs
#	src/scene/modify.rs

src/command.rs

@@ -2094,6 +2094,9 @@ pub enum CmdResult {
         handles: Vec<Handle>,
         axis_start: glam::DVec3,
         axis_end: glam::DVec3,
+        /// The line picked as the axis (Object), which an associative
+        /// surface keeps reading.
+        axis_object: Option<Handle>,
         angle: f64,
         start_angle: f64,
         mode: ExtrudeMode,