Add missing @extends for ws_transaction type
Add missing @extends for ws_reply type
Add missing @extends for ws_error_reply type
Add missing @extends for ws_value_reply type
Merge pull request #356 from matthiasbeyer/add-missing_extends_documentation

Add missing @extends for message subtypes
Add extensive documentation about the hotkey subsystem
Add files for hotkey subsystem
Add file for hotkey DAG implementation
Add interface definitions and stubs for DAG
Add initial hotkey event type
Add function for retrieving the next DAG node