Get the Jasmine tests working again -- these were broken by #49267cd
Fail-fast if a circular dependency is detected, but allow circular dependencies if the module has already exported at the point the circle forms.
Fixed bug recently introduced to Topiarist when improving it's circular
dependency detection -- will add unit tests around this when it's merged
upstream into the 'topiarist' project.
Improved the success-case circular depenendency test so that it verifies that what gets returened when a circular dependency has been detected is actually valid.
Merge pull request #4 from BladeRunnerJS/better-circular-dependency-detection

Better circular dependency detection