Templating improvements and directory creation tweaks

Added templating for another couple of files to the datastax recipe. Both the log and datacenter files were previously templated only when using that tar recipe. 

Split and moved about some directory creation stuff. It was happening before installing the packages but I can't see any reason for that, and the packages could create or set different permissions on those same directories. 

Some of them - like installation_dir - look like they should only be used by tar installs so I'm not sure why they're there. Assuming its a debian specific thing I've moved them inside the platform case statement. 

@Ottan may be able to test or confirm if they're needed there as they were from his commit. 

Also fixed up some file ownership to use the group attribute rather than setting the group to the username attribute.