Remove superfluous parameter puppet_hook.

* This parameter and the hook script it should control is never used.
* The linked hookscript is not roled out.
Introduce oned.conf hook config with hiera.

* Make oned.conf more flexible and allow custom hook scripts.
Cleanup some documentation.
Install hookscripts as package.
Merge pull request #69 from chrisN777/hookscript_cleanup

Make hookscript install + definition in oned.conf configurable + little cleanup