Add compilation results to gitignore
Specify types for notification fields
Add node_info struct
Add ruby classes to c extension
Move Zwave class into extra file
Add node and value ruby class
Add all_on/_off methods
Add value and node accessors to notification
Manage list of known nodes and their values
Fill ruby notification with notification data
Add rudimentary node methods
Add missing return statement
Add Value#label method
Define the actual ruby methods of the c extension