execs run continiously fix
Improve ZK initialization, which also fixes Wirbelsturm issue 25

The ZK init script purpose is effectively only to:
- Create the data directory, including a version-2 sub-directory
- Create the data log directory, including a version-2 sub-directory
- Create the myid file under the data directory

This commit lets Puppet handle the three resources above, which
simplifies the Puppet module and also makes it more resilient
because dependencies are better controlled now (the previous approach
made use of exec, which complicated resource dependency management).

See also:
https://github.com/miguno/wirbelsturm/issues/25
Add note about 'ruok' not being super helpful (rather use 'stat')
Update CHANGELOG
Merge branch 'master' of github.com:bazilek/puppet-zookeeper into zookeeper-init-fix
Update CHANGELOG
Update CHANGELOG