Added txread10 op to TimeOp.
Added txread10 op to TimeOp.

Performs multiple reads inside a single transaction, and measures the latency of
each.

jdellithorpe/RAMCloudUtils,jdellithorpe/RAMCloudTools,ellitron/RAMCloudTools,ellitron/RAMCloudTools,jdellithorpe/RAMCloudUtils,jdellithorpe/RAMCloudUtils,jdellithorpe/RAMCloudTools,ellitron/RAMCloudTools