Merge pull request #136 from philk/sorted_json

Make save_config sort JSON keys
Use lib.get_node instead of using _build_node_data_bag
Add parallel options
Change usage of _remove_local_node_data_bag and _remove_local_node_data_bag

Using these from the runner itself seems to make more sense
organizationally and allows us to only build the node data bags once at
the beginning of the run. That's especially important when we're running
multiple nodes in parallel.
Print the host string in more commands
Add _node_runner and make node use it

To enable parallelism we can't just call chef.sync_node from a for loop.
This uses Fabric's built in functions to run Chef on nodes in
parallel.