Ninja: fixed CHANGES.txt for CASSANDRA-7828
Potentially use non-local hosts in CqlConfigHelper

patch by jlewandowski; reviewed by alexliu68 for CASSANDRA-7906
Make CQLSSTableWriter sync within partitions

patch by slebresne; reviewed by blerer for CASSANDRA-7360
Update Xss in test/cassandra.in.sh

Done for CASSANDRA-7856
Fix for CQLSSTableWriter concurrent writers

- When a KS is already defined but a CF is new, the CQLSSTableWriter
  now properly registers the CF with the Schema
- Add a test for concurrent CQLSSTableWriters