Move production.log to /var/log/crowbar

We create the directory in the chef recipe, to be sure it's there (note
that it's using 0750 permissions to avoid leaking sensitive data).
Also move chef-client runs to /var/log/crowbar

They now live in /var/log/crowbar/chef-client.
Only create a .out log instead of .stdout/.stderr
Cleanup recipe code with a logdir variable