Fix console.debug checks

This fixes an error occurring in ```src/processors/stack.coffee``` due to there being no check and cleans up a check in ```src/reporters/jsonp.coffee``` to be done inline.

There's a third place that ```console.debug``` is called, but it has an if check that prevents logic from happening if ```console.debug``` isn't defined/a function.

Please let me know if there's anything else you need here.