Inject artificial events to make it look as if no loss occurs around directory creation

Files and directories found while recursively iterating in new directories currently do not get handlers invoked.

This means that if a user runs `mkdir -p a/b/c; touch a/b/c/d.txt` (particularly as a single compound command, to have very little time between their execution), there is no guarantee that their code will be notified about any creations other than `a`, even if `a/b` and `a/b/c` are iterated through when setting up handlers recursively.

Closes #6. Also closes #4 (touches the same code).