add verbose_logging config option to chef based provisioners

This pull requests add the [verbose_logging](http://wiki.opscode.com/display/chef/Chef+Configuration+Settings#ChefConfigurationSettings-logoutput) option to the solo.rb/client.rb.

I really like this option to identify chef resources that are executed unnecessary in every run. Especially when optimizing bigger run_lists it really helps (together with `log_level: info`) to fade out all resources then are not executed.