Rework/Enhance Node API

[tazend]

Branch is here

Classes

• Node class exposing all possible members of the C-struct as properties.
• Nodes class, acting as a custom collection (dict) to retrieve all Nodes, while also holding all the Node instances which carry the actual information for the invidiual Node.

General Functionality for a Node

• create
• modify
• delete
• get (getting a single node)

Other

• Documentation
• Write tests
• Write examples

[tazend]

Done with #283