First pass extracting connector API

Remove host_connector and host_commander code and specs
Remove winrm and ssh relating code

References to ssh and winrm have been removed in various places
Remove node "targeting" methods from the node_resource object
Remove unnecessary tests and remove some unneeded code
Remove the net-ssh and winrm gem dependencies
remove node resource references to bootstrapping
Merge pull request #227 from RiotGames/extract_connectors

Extract Connector classes to its own gem