Extract the dependency tracking to DependencyTracker
Use handler-specific dependency trackers
Clear up a confusing string
Make the test more readable
Avoid confusing the two fake template classes
Move the error handling back to TemplateDigestor
Use a thread safe tracker cache
Return an empty array if no tracker is registered for the handler
Rename ErbTracker -> ERBTracker
Rename #unregister_tracker to #remove_tracker
Register the tracker at load time
Use the right handler
Properly register the ERB tracker
Register trackers with extensions, not handlers
Remove trailing whitespace
Merge pull request #19 from dasch/refactor-dependency-tracking

Allow registering custom dependency trackers