Cruncher continued and rewritten to use states:

Cruncher continued and rewritten to use states:
- States 'init' and 'virgin' introduced
- Needed cruncher parts refactured to use the new states
- Creation of node/cruncher states is now done in factories
- Key producer added which will produce keys if the required state 'virgin' is
  beging detected. This producer works without a loop which is recommended for
  task-based applications
- A lot other improvements
- TODOs.txt updated