Circular Dependency Detection

[jasonmcaffee]

lib/modulus.js _recursivelyFindDependencies needs detection for circular dependencies.

What I would like is logic to detect that there is a circular dependency, and break out of recursion when it's detected.

e.g. moduleA depends on moduleB which depends on moduleC which depends on moduleA.

I haven't run into an issue with circular deps before, but I think it's a valid issue. http://stackoverflow.com/questions/4881059/how-to-handle-circular-dependencies-with-requirejs-amd