Examples updates

The node.js sys library has been a pointer to util since 0.3 and has now been removed completely in the node.js development branch. Also fix for changes to the fs API.

It should also be noted that [Promises have been removed](https://github.com/joyent/node/commit/c1aa8ea944072d224db42f8d05906f22702c9980), so examples/switch-bench.js doesn't work either. It should be refactored or removed.