Add --no-sync option to skip syncing and only run Chef

This option skips preparation and syncing of the kitchen and only runs chef solo on the node.

Our use case for this is to quickly run single recipes on the node via the -o option. Syncing adds a significant delay  which is unnecessary in this case since no changes to the kitchen were actually made. Typical runtime reductions for us are from 45s to 17s.

I can see you are working on ssh session caching which is great and will probably reduce overall runtimes a lot but this might still be a useful option.