rewrote corner extraction for clarity and simplicity.
Updated parameters to something that works with sample more generally.
1) lowered brisk detector threshold
2) removed scene gaussian since I figure in most cases the object will be better quality than the scene.
Cleaned up script a lot. Removed/reworded/added comments.
More robust search behavior:
1) Allow more features into "good features"
2) Fixed allowed scale range to be +/- 30%