Update Solr script to resolve issues with ZK and creating collection

I found few issues with the script creating Solr for Ranger.

1. If there are multiple hosts given in the ZK hosts, then it create ZK node fails
2. We should use bin/solr create_collection command to create the collection. Currently we are using curl command
3. Currently we are passing all argument via command line. It might be better to customize solr.in.sh and use it while calling bin/solr
4. Provide wrapper "solr" script to include SOLR_INCLUDE before calling bin/solr
5. Update documentation to make the setup more clear