Remove option added. Dependencies fixed.

This update of centerline-trace has seen several improvements.

• New feature: remove option to replace the bitmap with a vector graphics in one click.
• Execution speed is controlled by
  • limiting the megapixels per image sent to autotrace.
  • a user changeable number of candidate runs with autotrace. Default was 15, now 1, and still works great!
• Quality is controlled by
  • a despecle median filter
  • an equal brightness preprocessor (only needed with badly lit noisy photos)