CBQE-1281: support for xdcr query in systest

to specify queries to be ran on both local/remote site within same phase..ie
                 "query" : [{"remote" : "remote1" , "spec" : "ddoc:ddoc1,view:view1,qps:200"},
                             "{"spec" : ddoc:ddoc1,view:view1,qps:200"}]

Change-Id: Ie035e919668dc2f47bac20ef095e28f2f058ac21
Reviewed-on: http://review.couchbase.org/26205
Reviewed-by: Chisheng Hong <chisheng@couchbase.com>
Tested-by: Tommie McAfee <tommie@couchbase.com>