Adding Solr operator:

1. Input Operator: Reads data from Solr server based on user defined queries.
2. Output Operator: Writes data to Solr server.
3. Unit tests which uses embedded Solr Server.
4. resources file which needs to initialize embedded solr server for unit testing.
5. Demo app for Solr Input and Output operator
I think this check is not required , currentWindo will always be greater than lastProcessedWindow