Add another layer of indirection for coordinates and begin integrating new constraint system.
Fix problem with state-patches only one level deep.
Reordering constraint code path.
Same constraint works, but very slowly, and constraint solver doesn't know to prefer the value that comes from user input.
Constraints are more stable.

- Improve speed by doing whole-pixel changes each round of relaxation.
- Fix logic error and infinite slope case error in colinearity constraint.