updates resolveConstraints to the new optimization classes, and updates inspector to use resolveConstraints effectively

also made inspector a little nicer in general (handles window resizing, shows variable values, etc)
ended up implementing user gradients for the stateConstraints method in RBM to speed things up.
now we can play with systems with four-bar linkages at interactive rates using the inspector, and it behaves pretty nicely.

Should this line just be 
```matlab
success = false;
```
since we assign a new random `x0` on line 66?