changes in BLI_kdopbvh: - `BLI_bvhtree_find_nearest_to_ray` now takes is_ray_normalized and scale argument. - `BLI_bvhtree_find_nearest_to_ray_angle` has been added (use for perspective view). changes in BLI_bvhutils: - `bvhtree_from_editmesh_edges_ex` was added. changes in math_geom: - `dist_squared_ray_to_seg_v3` was added. other changes: - `do_ray_start_correction` is no longer necessary to snap to verts. - the way in which the test of depth was done before is being simulated in callbacks.