[CDH5] Convert tpch schemas to decimal and change the queries where possible.

I used the following document for reference: http://www.tpc.org/tpch/spec/tpch2.1.0.pdf

Change-Id: Ic84db0628323c90e89552707f214bbb9fa2f2ae0
Reviewed-on: http://gerrit.ent.cloudera.com:8080/3132
Reviewed-by: Ishaan Joshi <ishaan@cloudera.com>
Tested-by: jenkins