cassandra master datasource reader
Merge pull request #14 from dhanuka84/master

cassandra master datasource reader
Make external cassandra property optional as per SS-367
two mode support: Cluster and Session
Merge pull request #16 from dhanuka84/master

two mode support: Cluster and Session
Merge pull request #15 from harsha89/SS-367

Make external cassandra property optional as per SS-367
handle defaults
Merge pull request #17 from dhanuka84/master

handle defaults
cassandra data reader feature
Merge pull request #18 from dhanuka84/master

cassandra data reader feature