added most code for process_pyramids_barrier():
  Geometry.py now compares float() using _eps: new functions: colinear(), intersect_lines(), intersect_x(), intersect_y(), Barrier.find(), Barrier.point()
  Strategy.py new functions: shortcut_segment() TBD, subdivide_segment(), unlink_segment() TBD, output_add() TBD.
  Improved prose and code in process_pyramids_barrier()
  Tested most new code with a fake trigger check.