Updated libdxf.pot.
Update build.sh
SURFACE: added dxf_surface_swept_struct.
SURFACE: added dxf_surface_swept_new().
SURFACE: added dxf_surface_swept_free().
SURFACE: added dxf_surface_swept_free_list().
SURFACE: added dxf_surface_swept_get_p1().
SURFACE: added dxf_surface_swept_set_p1().