RedHat support

Tested your module on CentOS6 and found its partial RedHat support not working:

- Standard Config path for Redhat should be /etc/cassandra/conf/ not /etc/cassandra/ 
- File permissions fixed to cassandra:cassandra, otherwise data/log dir/files are wrong
- python-cql is called python26-cql on Redhat

You still have to take care of /etc/alternatives/cassandra pointing to the correct config path yourself by alternatives --install ....