Services node resource extension

Extends functionality for the node resource available through services module.

Additional Authentication:
- Provides the ability to define a specific node type (or types) that requests
made to node resources can have access to.

Additional Resources:
- lookup - provides a resource to request a node through the url alias.
- POST data = [
'alias' => the url alias.
]
- autocomplete - provides a resource to search for a node(s) by node title.
- POST data = [
'title' => node title to search for.
'exact_match' => 1/0, perform a search for exact title.
]
- publish - provides a resource to publish a node.
- URL argument - NID.
- unpublish - provides a resource to unpublish a node.
- URL argument - NID.