Debugger

[ysthakur]

Since for golfing languages, most of the execution time is spent inside the implementations of the built-ins rather than the interpreter, a common golfing runtime doesn't have a huge advantage over a plain library of common built-ins. However, adding a debugger to the runtime would be a pretty big advantage over a library. While it's a pretty big task to undertake, we might want to start design the runtime with a debugger in mind, so it won't be too hard (or impossible) to add a debugger down the line. Thoughts?