querycmd: Add support for create index, drop index and list index

Example:

CREATE:
Secondary index:
$ ./querycmd -type create -bucket default -index first_name -server localhost:9101 -fields=first_name,lastname

Primary index:
./querycmd -type create -bucket default -server localhost:9101 -primary=true

DROP:
./querycmd -type drop -instanceid 1234 -server localhost:9101

LIST:
./querycmd -type list -server localhost:9101

Change-Id: Ieddb91c759d9fa701de77deaffcea8b7f81682be
Reviewed-on: http://review.couchbase.org/43839
Reviewed-by: Pratap Chakravarthy <prataprc@couchbase.com>
Reviewed-by: Sarath Lakshman <sarath@couchbase.com>
Tested-by: Sarath Lakshman <sarath@couchbase.com>