add params in benchmark tasks for number and length
add params in benchmark tasks for number and length

quixoten/protobuf,zanker/protobuf,film42/protobuf,ruby-protobuf/protobuf,film42/protobuf,brianstien/protobuf,lookout/protobuffy,zanker/protobuf,ruby-protobuf/protobuf,quixoten/protobuf,localshred/protobuf,localshred/protobuf,lookout/protobuffy,brianstien/protobuf