Improving permissions/ownership of config files.

 - configuration files should be owned by root
 - $apache_user should not be able to modify configuration files
 - introducing $apache_group parameter to the puppetdashboard class
 - passing $apache_user and $apache_group parameters to
   puppetdashboard::config
Merge pull request #9 from sedden/config_permissions_ownership

Improving permissions/ownership of config files.

Thanks!